improve how markdown code language is commented

We added a space between the markdown triple code mark
and language that was enclosed in HTML comments.

So a line of the form:

````
```<!---c--->
````

became:

````
``` <!---c--->
````

This was done to **help** some code see that the HTML comment
string was not a markdown code specifier.   Not all code
understands this after this changed.  For example, `pandoc(1)`
still forms HTML classes of the form "&lt;!---c--&gt;"
when it encounters the above mentioned change.

We also fixed a problem with `2019/dogon/README.md` regarding
a markdown code block.

We also fixed a problem with `2020/yang/README.md` regarding
a markdown code block.

1994/dodsond1/README.md

@@ -1,13 +1,13 @@
 ## To build:
 
-```<!---sh-->
+``` <!---sh-->
     make all
 ```
 
 
 ## To use:
 
-```<!---sh-->
+``` <!---sh-->
     ./dodsond1
 ```
 

1994/dodsond2/README.md

@@ -1,6 +1,6 @@
 ## To build:
 
-```<!---sh-->
+``` <!---sh-->
     make all
 ```
 
@@ -23,7 +23,7 @@ For more detailed information see [1994 dodsond2 bugs](../../bugs.html#1994_dods
 
 ## To use:
 
-```<!---sh-->
+``` <!---sh-->
     ./dodsond2
 ```
 
@@ -39,21 +39,21 @@ from working in some cases.
 
 ### Alternate build:
 
-```<!---sh-->
+``` <!---sh-->
     make alt
 ```
 
 The default number of arrows in this version is 3 but if you want to change it,
 say to 5, try:
 
-```<!---sh-->
+``` <!---sh-->
     make clobber ARROWS=5 alt
 ```
 
 
 ### Alternate use:
 
-```<!---sh-->
+``` <!---sh-->
     ./dodsond2.alt
 ```
 

1994/horton/README.md

@@ -1,13 +1,13 @@
 ## To build:
 
-```<!---sh-->
+``` <!---sh-->
     make all
 ```
 
 
 ## To use:
 
-```<!---sh-->
+``` <!---sh-->
     ./horton A B C D
 ```
 
@@ -16,7 +16,7 @@
 
 ## Try:
 
-```<!---sh-->
+``` <!---sh-->
     ./try.sh
 ```
 
@@ -29,14 +29,14 @@ version.
 
 ### Alternate build:
 
-```<!---sh-->
+``` <!---sh-->
     make alt
 ```
 
 
 ### Alternate use:
 
-```<!---sh-->
+``` <!---sh-->
     ./horton.alt A B C D
 ```
 
@@ -45,7 +45,7 @@ Where A, B, C and D are numbers like with `horton`.
 
 ### Alternate try:
 
-```<!---sh-->
+``` <!---sh-->
     ./try.alt.sh
 ```
 
@@ -80,7 +80,7 @@ It's easily modified to graph *any* 96x160 bitmap on a dumb terminal.
 
 See the [gtface](gtface.c) program for another example.  Try:
 
-```<!---sh-->
+``` <!---sh-->
     make gtface
     ./gtface < gtface.data
 ```

1994/imc/README.md

@@ -1,13 +1,13 @@
 ## To build:
 
-```<!---sh-->
+``` <!---sh-->
     make all
 ```
 
 
 ## To use:
 
-```<!---sh-->
+``` <!---sh-->
     ./imc [NUMBER]
 ```
 
@@ -16,7 +16,7 @@ where `[NUMBER]` is an optional number. Default is 5.
 
 ## Try:
 
-```<!---sh-->
+``` <!---sh-->
     ./try.sh
 ```
 

1994/ldb/README.md

@@ -1,6 +1,6 @@
 ## To build:
 
-```<!---sh-->
+``` <!---sh-->
     make all
 ```
 
@@ -18,7 +18,7 @@ For more detailed information see [1994 ldb bugs](../../bugs.html#1994_ldb).
 
 ## To use:
 
-```<!---sh-->
+``` <!---sh-->
     ./ldb < file
 
     some_command | ./ldb
@@ -27,7 +27,7 @@ For more detailed information see [1994 ldb bugs](../../bugs.html#1994_ldb).
 
 ## Try:
 
-```<!---sh-->
+``` <!---sh-->
     ./try.sh
 ```
 

1994/schnitzi/README.md

@@ -1,6 +1,6 @@
 ## To build:
 
-```<!---sh-->
+``` <!---sh-->
     make all
 ```
 
@@ -23,14 +23,14 @@ For more detailed information see [1994 schnitzi bugs](../../bugs.html#1994_schn
 
 ## To use:
 
-```<!---sh-->
+``` <!---sh-->
     ./schnitzi < textfile
 ```
 
 
 ## Try:
 
-```<!---sh-->
+``` <!---sh-->
     ./try.sh
 ```
 
@@ -49,7 +49,7 @@ buffer size. This is due to a comment which is explained in more detail in
 
 ### Alternate build:
 
-```<!---sh-->
+``` <!---sh-->
     make alt
 ```
 
@@ -62,7 +62,7 @@ feeding the source code to it will not work right.
 
 ### Alternate try:
 
-```<!---sh-->
+``` <!---sh-->
     ./try.alt.sh
 ```
 
@@ -71,7 +71,7 @@ feeding the source code to it will not work right.
 
 Try:
 
-```<!---sh-->
+``` <!---sh-->
     ./schnitzi < schnitzi.c
 ```
 
@@ -96,14 +96,14 @@ is run by redirecting a file into the executable on the command
 line; for instance, for the file 'info', the program
 would be run as follows:
 
-```<!---sh-->
+``` <!---sh-->
     ./schnitzi < info
 ```
 
 The program generates interesting results when its source file is
 used as input:
 
-```<!---sh-->
+``` <!---sh-->
     ./schnitzi < schnitzi.c
 ```
 

1994/shapiro/README.md

@@ -1,6 +1,6 @@
 ## To build:
 
-```<!---sh-->
+``` <!---sh-->
     make all
 ```
 
@@ -19,7 +19,7 @@ For more detailed information see [1994 shapiro bugs](../../bugs.html#1994_shapi
 
 ## To use:
 
-```<!---sh-->
+``` <!---sh-->
     ./shapiro &
 ```
 
@@ -28,7 +28,7 @@ Now find the clock in the same terminal window (or console if at the console).
 
 ## Try:
 
-```<!---sh-->
+``` <!---sh-->
     ./shapiro
     ^Z
     bg

1994/smr/README.md

@@ -1,20 +1,20 @@
 ## To build:
 
-```<!---sh-->
+``` <!---sh-->
     make all
 ```
 
 
 ## To use:
 
-```<!---sh-->
+``` <!---sh-->
     ./smr
 ```
 
 
 ## Try:
 
-```<!---sh-->
+``` <!---sh-->
     ./try.sh
 ```
 

1994/tvr/README.md

@@ -1,6 +1,6 @@
 ## To build:
 
-```<!---sh-->
+``` <!---sh-->
     make all
 ```
 
@@ -22,7 +22,7 @@ For more detailed information see [1994 tvr bugs](../../bugs.html#1994_tvr).
 
 ## To use:
 
-```<!---sh-->
+``` <!---sh-->
     ./tvr mode screensize/2 < colormapfile
 ```
 
@@ -31,7 +31,7 @@ Mode may be a value from 0 to 12.
 
 ## Try:
 
-```<!---sh-->
+``` <!---sh-->
     ./try.color.sh			# for colour displays
     ./try.bw.sh			# for Black & White displays
 ```
@@ -44,14 +44,14 @@ The author provided us a spoiler version that might be of interest to some.
 
 ### Alternate build:
 
-```<!---sh-->
+``` <!---sh-->
     make alt
 ```
 
 
 ### Alternate use:
 
-```<!---sh-->
+``` <!---sh-->
     ./tvr.alt altmode screensize/2 < colormapfile
 ```
 
@@ -61,7 +61,7 @@ where `altmode` `1` - `4` correspond to mode `0` - `3` in the original entry and
 
 ### Alternate try:
 
-```<!---sh-->
+``` <!---sh-->
     ./try.alt.color.sh			# for colour displays
     ./try.alt.bw.sh			# for Black & White displays
 ```
@@ -123,7 +123,7 @@ the fourth is a variation of that with more nice effects.
 
 ### Usage:
 
-```<!---sh-->
+``` <!---sh-->
     ./tvr mode screensize/2 < colormapfile
 ```
 

1994/weisberg/README.md

@@ -1,6 +1,6 @@
 ## To build:
 
-```<!---sh-->
+``` <!---sh-->
     make all
 ```
 
@@ -10,20 +10,20 @@ code](#alternate-code) below for more details.
 
 ## To use:
 
-```<!---sh-->
+``` <!---sh-->
     ./weisberg
 ```
 
 
 ## Try:
 
-```<!---sh-->
+``` <!---sh-->
     ./try.sh
 ```
 
 If you have `primes(1)` installed you might also wish to try:
 
-```<!---sh-->
+``` <!---sh-->
     ./primes.sh number
 ```
 
@@ -40,14 +40,14 @@ something with you might try this version.
 
 ### Alternate build:
 
-```<!---sh-->
+``` <!---sh-->
     make alt
 ```
 
 
 ### Alternate use:
 
-```<!---sh-->
+``` <!---sh-->
     ./weisberg.alt
 ```
 

1994/westley/README.md

@@ -1,6 +1,6 @@
 ## To build:
 
-```<!---sh-->
+``` <!---sh-->
     make alt
 ```
 
@@ -15,7 +15,7 @@ see [Original code](#original-code) below.
 
 ## To use:
 
-```<!---sh-->
+``` <!---sh-->
     ./westley.alt
 ```
 
@@ -39,14 +39,14 @@ from start to finish.
 For something more interesting try compiling it with different `cc -D` arguments
 and then run the program each time.  For example:
 
-```<!---sh-->
+``` <!---sh-->
     cc -Describe -Door westley.alt.c -o westley.alt && ./westley.alt
     cc -Describe -Drain westley.alt.c -o westley.alt && ./westley.alt
 ```
 
 To see the game from start to finish, try:
 
-```<!---sh-->
+``` <!---sh-->
     ./try.alt.sh
 ```
 
@@ -65,7 +65,7 @@ reason that we recommend you try it first.
 
 ### Original build:
 
-```<!---sh-->
+``` <!---sh-->
     make all
 ```
 
@@ -95,14 +95,14 @@ error messages; there is no running the program.
 For something more interesting try compiling it with different `cc -D`
 arguments:
 
-```<!---sh-->
+``` <!---sh-->
     cc -Describe -Door westley.c
     cc -Describe -Drain westley.c
 ```
 
 To see the game from start to complete, try:
 
-```<!---sh-->
+``` <!---sh-->
     ./try.sh
 ```
 
@@ -115,7 +115,7 @@ For spoilers see the end of the notes from the author below.
 
 To use:
 
-```<!---sh-->
+``` <!---sh-->
     ./try.sh
 ```
 
@@ -131,7 +131,7 @@ This program is a simple adventure game which uses only C preprocessor
 error messages (for missing `#include` files) as output.  To begin,
 try to compile the program with no options:
 
-```<!---sh-->
+``` <!---sh-->
     cc westley.c
 ```
 
@@ -159,7 +159,7 @@ missing include file name, which functions as the game text.
 To "do" things, all words must start with `-D`.  For example, to
 look at the door, do:
 
-```<!---sh-->
+``` <!---sh-->
     cc -Describe -Door prog.c
 ```
 
@@ -176,7 +176,7 @@ Here is a walk-through for the game, including a few dead-ends:
 
 ### SPOILER
 
-```<!---sh-->
+``` <!---sh-->
     cc -Describe -Door westley.c
     cc -Describe -Drain westley.c
     cc -Describe -Dwarf westley.c