Rename *.text *.md

As luck would have it the only entries where this applied were my own.
The links/references to these files have been changed in the files.

An unfortunate problem is that in 2020/ferguson1 there are several
*.markdown files. I will have to go through these and figure out which
ones should be changed to .md and which ones can be removed. This can
happen later but in the meantime the references are to .md. I believe
the only difference is that the .md has the footer added by the judges.
This was a workaround with the fact that I wasn't sure (and still am not
entirely sure) the generation of the html files will work. It might be
that the .markdown files have the footer and the .md files do not but
this can be dealt with later anyway.

2020/ferguson1/README.md

@@ -37,19 +37,19 @@ This game has a number of configurable pitfalls including walls and snakes.
 
 There is a good deal of useful documentation that is provided with this entry:
 
-* gameplay.markdown ([gameplay.html][])
+* gameplay.md ([gameplay.html][])
 
 Documented game *features*!
 
-* terminals.markdown ([terminals.html][])
+* terminals.md ([terminals.html][])
 
 Information about terminal capabilities, dimensions (setting and how to restore sanity if it causes any problems) as well as colours (limitations etc.).
 
-* troubleshooting.markdown ([troubleshooting.html][])
+* troubleshooting.md ([troubleshooting.html][])
 
 Workaround for various game *features*
 
-* bugs.markdown ([bugs.html][])
+* bugs.md ([bugs.html][])
 
 Bugs and things that might seem like bugs but are not.
 
@@ -75,7 +75,7 @@ Snake has two cheat modes (passable walls and self [cannibalism]), a drawing (or
 practising) mode, *can play by itself (**and win!**)*, is coloured (included
 [snake-colours.sh][] and [play.sh][] scripts compile in player-selected
 colours) and there are many other play modes (many more can be devised with the
-imagination and the environmental variables; see [gameplay.markdown][] /
+imagination and the environmental variables; see [gameplay.md][] /
 [gameplay.html][] for many examples) and options.  You can pause and there's
 even a built-in test unit for some features!  The following variables change the
 game in the following ways (all can be combined):
@@ -112,16 +112,16 @@ game in the following ways (all can be combined):
     included in the relevant section (this goes for a low **EVADE** value too).
 
 *   Grow-Shrink mode (Positive and Negative Winning) mode (see
-    [gameplay.markdown][] for more details).
+    [gameplay.md][] for more details).
 
 *   The dimensions of the game (this is actually a terminal thing but I document
     how to do this and its potential pitfalls) (**LINES** , **COLUMNS**).
 
 There are no complicated command line invocations; it's just a matter of passing
 into the game descriptively named variables and I include a script that sets up
-many different gameplay modes ([gameplay.markdown][] and [play.sh][]).
+many different gameplay modes ([gameplay.md][] and [play.sh][]).
 
-The [gameplay.markdown][] ([gameplay.html][]) file has all the information on
+The [gameplay.md][] ([gameplay.html][]) file has all the information on
 what the game looks like, how to play, the different types of modes (that I have
 thought of so far) including all those in the above list. Along with the
 [play.sh][] and [snake-colours.sh][] scripts it's probably the most important
@@ -139,18 +139,18 @@ Probably just as important is [chocolate-cake.html][] with an old but wonderful
 recipe (because the judges love chocolate and who can blame them? - also it goes
 with one of the IAQs I include later).
 
-The [troubleshooting.markdown][] ([troubleshooting.html][]) file has some advice
+The [troubleshooting.md][] ([troubleshooting.html][]) file has some advice
 on potential problems (and things that might appear to be problems at first
 glance but are not) that I have thought of or encountered.
 
-The [terminals.markdown][] ([terminals.html][]) has a variety of information
+The [terminals.md][] ([terminals.html][]) has a variety of information
 specific to terminals from input/directions, dimensions, sanity and colours: a
 sort of troubleshooting guide for terminals with some additional information.
 
 The [spoilers.markdown][] has a variety of information including some of the
 obfuscation techniques and a bit of how it works.
 
-The [bugs.markdown][] ([bugs.html][]) has a list of known bugs and things that
+The [bugs.md][] ([bugs.html][]) has a list of known bugs and things that
 look like bugs but aren't as well as documenting a built-in test unit for some
 features.
 
@@ -222,7 +222,7 @@ and [troubleshooting.html][] - along with the most important one
     took fewer bytes and the negative shedding is a positive consequence of
     unsigned arithmetic.
 
-On a more serious note look at [bugs.markdown][] ([bugs.html][]).
+On a more serious note look at [bugs.md][] ([bugs.html][]).
 
 
 ### <a name="naqs" href="#toc">NAQs/IAQs (Never/Infrequently Asked Questions)</a>
@@ -453,18 +453,18 @@ both do.
 
 [COMPILING]: COMPILING
 [HACKING]: HACKING
-[bugs.markdown]: bugs.markdown
+[bugs.md]: bugs.md
 [bugs.html]: bugs.html
-[troubleshooting.markdown]: troubleshooting.markdown
+[troubleshooting.md]: troubleshooting.md
 [troubleshooting.html]: troubleshooting.html
 [human snakes]: http://www.macroevolution.net/snake-human-hybrids.html
 [chocolate-cake.html]: chocolate-cake.html
 [spoilers.markdown]: spoilers.markdown
-[terminals.markdown]: terminals.markdown
+[terminals.md]: terminals.md
 [Surround]: https://en.wikipedia.org/wiki/Surround_(video_game)
 [Snake walk: The physics of slithering]: https://www.bbc.co.uk/news/science-environment-35563941
 [snake-colours.sh]: snake-colours.sh
-[gameplay.markdown]: gameplay.markdown
+[gameplay.md]: gameplay.md
 [gameplay.html]: gameplay.html
 [flying snakes]: https://www.bbc.co.uk/news/science-environment-25943693
 [play.sh]: play.sh