fix internal links in entry index.html from 1984 thru 2012

2004/arachnid/README.md

@@ -73,7 +73,7 @@ characters as walls.
 Feed the program its own source for a default maze. Running it with no command
 line parameters will do this. In a nice symmetry, the character constant `~`
 that recognises exits to input mazes itself forms the exit to the default maze.
-Another maze, [arachnid.txt](arachnid.txt) has also been provided. This maze is
+Another maze, [arachnid.txt](%%REPO_URL%%/2004/arachnid/arachnid.txt) has also been provided. This maze is
 255x255, about the largest maze supported, for the particularly insane maze
 explorers out there.
 

2004/arachnid/index.html

@@ -189,7 +189,7 @@ characters as walls.</p>
 <p>Feed the program its own source for a default maze. Running it with no command
 line parameters will do this. In a nice symmetry, the character constant <code>~</code>
 that recognises exits to input mazes itself forms the exit to the default maze.
-Another maze, <a href="arachnid.txt">arachnid.txt</a> has also been provided. This maze is
+Another maze, <a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/2004/arachnid/arachnid.txt">arachnid.txt</a> has also been provided. This maze is
 255x255, about the largest maze supported, for the particularly insane maze
 explorers out there.</p>
 <h3 id="usage">Usage</h3>