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.

1985/lycklama/README.md

@@ -1,13 +1,13 @@
 ## To build:
 
-```<!---sh-->
+``` <!---sh-->
     make alt
 ```
 
 
 ## To use:
 
-```<!---sh-->
+``` <!---sh-->
     ./lycklama.alt < some_file
 ```
 
@@ -24,13 +24,13 @@ call with a configurable time to sleep. The default is 500 microseconds but you
 reconfigure it like:
 
 
-```<!---sh-->
+``` <!---sh-->
     make SLEEP=700 clobber alt
 ```
 
 which would set it at 700. Then, whether you use the default value or not, try:
 
-```<!---sh-->
+``` <!---sh-->
     ./try.alt.sh
 ```
 
@@ -45,21 +45,21 @@ modern systems.
 
 ### Original build:
 
-```<!---sh-->
+``` <!---sh-->
     make all
 ```
 
 
 ### Original use:
 
-```<!---sh-->
+``` <!---sh-->
     ./lycklama < some_file
 ```
 
 
 ### Original try:
 
-```<!---sh-->
+``` <!---sh-->
     ./lycklama < lycklama.c
     ./lycklama < lycklama.alt.c
     ./lycklama < lycklama.orig.c