Remove reference to mirrors in index.html files

There are places where references to mirror sites should be kept in like
in the FAQ (currently FAQ 6.2 with the title 'May I mirror the IOCCC
website?' and with the named anchor 'mirrors', 'website_mirrors' and
'website_mirroring').

2001/README.md

@@ -8,9 +8,6 @@ on how to compile it and how to run the winning program.
 Look at the winning source and try to figure how it does what it does!
 You may then wish to look at the Author's remarks for even more details.
 
-The IOCCC has a website and now has a number of international mirrors.  The
-primary site can be found at [www.ioccc.org](https://www.ioccc.org).
-
 Some ANSI C compilers are not quite as good as they should be.  If
 yours is lacking, you may need to compile using gcc instead of your
 local compiler.

2001/index.html

@@ -398,8 +398,6 @@
 on how to compile it and how to run the winning program.
 Look at the winning source and try to figure how it does what it does!
 You may then wish to look at the Author’s remarks for even more details.</p>
-<p>The IOCCC has a website and now has a number of international mirrors. The
-primary site can be found at <a href="https://www.ioccc.org">www.ioccc.org</a>.</p>
 <p>Some ANSI C compilers are not quite as good as they should be. If
 yours is lacking, you may need to compile using gcc instead of your
 local compiler.</p>