fix many internal links

Fixed a number of internal links that need to
go to the GitHub site.

Ran `make www` to perform the above.

2000/tomx/README.md

@@ -4,7 +4,7 @@
     make
 ```
 
-There is an alternate version that compiles [mkentry.c](mkentry.c). See
+There is an alternate version that compiles [mkentry.c](%%REPO_URL%%/2000/mkentry.c). See
 [alternate code](#alternate-code).
 
 

2000/tomx/index.html

@@ -379,7 +379,7 @@ Location: <a href="../../location.html#NL">NL</a> - <em>Kingdom of the Netherlan
 <!-- BEFORE: 1st line of markdown file: 2000/tomx/README.md -->
 <h2 id="to-build">To build:</h2>
 <pre><code>    make</code></pre>
-<p>There is an alternate version that compiles <a href="mkentry.c">mkentry.c</a>. See
+<p>There is an alternate version that compiles <a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/2000/mkentry.c">mkentry.c</a>. See
 <a href="#alternate-code">alternate code</a>.</p>
 <h2 id="to-use">To use:</h2>
 <pre><code>    ./tomx</code></pre>