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').

2005/README.md

@@ -15,9 +15,6 @@ local compiler.
 This year we included most of the information included by the submitters
 in the `README.md` files (that were used to build the `index.html` web pages).
 
-The IOCCC has a website and now has a number of international mirrors.
-The primary website can be found at <https://www.ioccc.org/>.
-
 
 ## Remarks on some of the entries
 

2005/index.html

@@ -403,8 +403,6 @@ yours is lacking, you may need to compile using <code>gcc</code> instead of your
 local compiler.</p>
 <p>This year we included most of the information included by the submitters
 in the <code>README.md</code> files (that were used to build the <code>index.html</code> web pages).</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/" class="uri">https://www.ioccc.org/</a>.</p>
 <h2 id="remarks-on-some-of-the-entries">Remarks on some of the entries</h2>
 <p>We believe you will be impressed with this year’s winning entries.</p>
 <p>In particular:</p>