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').

2011/README.md

@@ -13,9 +13,6 @@ 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.
 
-The IOCCC has a website and now has a number of international mirrors.
-The primary website can be found at [www.ioccc.org](https://www.ioccc.org).
-
 
 ## Remarks on some of the entries
 

2011/index.html

@@ -402,8 +402,6 @@ year we included most of the information by the submitters).</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>
-<p>The IOCCC has a website and now has a number of international mirrors.
-The primary website can be found at <a href="https://www.ioccc.org">www.ioccc.org</a>.</p>
 <h2 id="remarks-on-some-of-the-entries">Remarks on some of the entries</h2>
 <p>There were some outstanding entries that did not win. Unfortunately
 some very good entries lost because they:</p>