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.

2020/endoh2/index.html

@@ -387,10 +387,10 @@ Location: <a href="../../location.html#JP">JP</a> - <em>Japan</em></li>
 <pre><code>    ./prog prog.c</code></pre>
 <p>?</p>
 <h2 id="judges-remarks">Judges’ remarks:</h2>
-<p>Clever use of the C99 complex data type. The <a href="spoiler/">spoiler</a> directory
+<p>Clever use of the C99 complex data type. The <a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/2020/endoh2/spoiler/spoiler.html">spoiler</a> directory
 contains clues as to how some winning authors create / edit programs into ASCII
 shapes.</p>
-<p>With the source from the <a href="spoiler/">spoiler</a> directory could you make the code
+<p>With the source from the <a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/2020/endoh2/spoiler/spoiler.html">spoiler</a> directory could you make the code
 render for a larger terminal window? How about adding more glyphs?</p>
 <h2 id="authors-remarks">Author’s remarks:</h2>
 <p>No! Try not. Do, or do not. There is no try.</p>