fix links in entry HTML files other than index.html

Fixed internal links in entry HTML files other than index.html.

Removed links to markdown files that otherwise used to
generate HTML files other than index.html.

Ran `make gen_other_html` to perform the above.

2020/ferguson1/COMPILING.md

@@ -4,7 +4,8 @@ will need two different packages: the library itself but also the dev package
 that has the header files etc. If you use the Makefile obviously you need `make`
 too.
 
-In [gameplay.md](gameplay.md) I show how to easily customise the colours, set up
+In [gameplay.html](%%REPO_URL%%/2020/ferguson1/gameplay.html)
+I show how to easily customise the colours, set up
 different gameplay modes and various other things. The troubleshooting.md
 and terminals.md as well as bugs.md include a variety of information
 should you run into trouble.
@@ -110,8 +111,6 @@ If it's an unsigned int I believe you will have to opt for an unsigned long (so
 Anything else I do not know other than just changing the typedef and updating to
 the proper function (and/or cast to the right type).
 
-[MacPorts]: https://www.macports.org
-
 
 <hr style="width:10%;text-align:left;margin-left:0">