replace obsolete a name tags with div

This HTML is now obsolete in HTML 5:

```html
<a name="faq0"></a>Section 0: Submitting entries to a new IOCCC
```

Instead we need to use the div HTML elements:

```html
<div id="faq0">Section 0: Submitting entries to a new IOCCC</div>
```

We are testing a fix for the top level HTML files.

Run `make gen_top_html` to perform the above and test under macOS.

TODO: Apply this type of fix across the entire web site if all is well.

bin/index.html

@@ -118,7 +118,7 @@
 <!-- END: this line ends content from: inc/begin-rightcolumn.default.html -->
 <!-- START: this line starts content from: inc/before-content.default.html -->
 
-    <a name="content"></a>
+    <div id="content">
 
 <!-- END: this line ends content from: inc/before-content.default.html -->
 <!-- START: this line starts content for HTML phase 21 by: bin/pandoc-wrapper.sh via bin/md2html.sh -->
@@ -320,7 +320,10 @@ We sort with lines starting with <code>!</code> fourth.</p>
 <pre><code>bin/all-years.sh -v 3 bin/untar-year.sh -v 1</code></pre>
 <p>We recommend that this tool be invoked via the top level <code>Makefile</code>:</p>
 <pre><code>make untar_year_tarball</code></pre>
-<h1 id="how-ioccc-html-content-is-built"><a name="how"></a>How IOCCC HTML content is built</h1>
+#
+<div id="how">
+How IOCCC HTML content is built
+</div>
 <p>The <a href="md2html.sh">md2html.sh</a> tool is the primary tool that
 is used to form all IOCCC related HTML pages for the <a href="https://www.ioccc.org">official IOCCC web
 site</a>.</p>
@@ -347,7 +350,10 @@ used during the <em>topnav</em> HTML phase.</p>
 For example:</p>
 <pre><code>-H footer=.</code></pre>
 <p>will cause no HTML content to be produced during the <code>footer</code> HTML phase.</p>
-<h2 id="html-phases"><a name="html"></a>HTML phases</h2>
+##
+<div id="html">
+HTML phases
+</div>
 <p>The following HTML phase files are used to build HTML content:</p>
 <ol start="0" type="1">
 <li>inc/top.default.html</li>
@@ -384,7 +390,10 @@ tool’ (<code>-p tool</code>), and the ‘after tool’ (<code>-a tool</code>)
 substituted).</p>
 <p>See the tool <a href="readme2index.sh">readme2index.sh</a> for an example of
 how HTML phases are implemented.</p>
-<h2 id="getopt-phase-processing-of-the-command-line"><a name="`getopt`"></a><code>getopt</code> phase processing of the command line</h2>
+##
+<div id="getopt">
+<code>getopt</code> phase processing of the command line
+</div>
 <p>The command options are evaluated in the following <code>getopt</code> phases:</p>
 <h3 id="getopt-phase-0"><code>getopt</code> phase 0</h3>
 <p>In <code>getopt</code> phase 0 we parse command line options and save all arguments for the
@@ -483,7 +492,10 @@ situation will not impact <strong>MOST</strong> of the HTML content.</p>
 <p>You may wonder why we need these files in the first place. You may wonder why
 we even need the tools in the <a href="index.html">bin</a> directory when there other
 solutions available to form web pages.</p>
-<h2 id="static-web-pages-only"><a name="static-only"></a>Static web pages only</h2>
+##
+<div id="static-only">
+Static web pages only
+</div>
 <p>Here are some reasons why we are using these files and
 special tools to create HTML content / IOCCC web pages:</p>
 <p>We host <a href="https://www.ioccc.org">official IOCCC web site</a> via <a href="https://pages.github.com">GitHub
@@ -497,7 +509,10 @@ pages</a>.</p>
 <h2 id="we-cannot-use-a-back-end-database">We cannot use a back-end database</h2>
 <p>We use <a href="#static-only">static web pages</a>, so use of a “back-end database” is not
 available to the IOCCC.</p>
-<h2 id="we-cannot-use-non-github-web-servers"><a name="why-github"></a>We cannot use non-GitHub web servers</h2>
+##
+<div id="why-github">
+We cannot use non-GitHub web servers
+</div>
 <p>The <a href="https://pages.github.com">GitHub pages</a> have the distributed server capacity needed to handle
 the <strong>huge download volume</strong> or <a href="https://en.wikipedia.org/wiki/Slashdot_effect">Slashdot effect</a>
 that happens when a IOCCC entries are published.</p>
@@ -544,7 +559,10 @@ disabled.</p>
 <p>The IOCCC will <strong>NOT MANDATE USE OF JavaScript</strong> to view <a href="https://www.ioccc.org">official IOCCC web
 site</a>.</p>
 <p>For this reason, we cannot use JavaScript include HTML content.</p>
-<h1 id="ioccc-terms"><a name="terms"></a>IOCCC terms</h1>
+#
+<div id="terms">
+IOCCC terms
+</div>
 <p>The following IOCCC terms apply to tools, JSON files, and the directory structure of this repo.</p>
 <h2 id="author"><code>author</code></h2>
 <p>An individual who was an <code>author</code> of at least one winning IOCCC entry.</p>
@@ -632,6 +650,8 @@ is directly under a <code>year</code> directory.</p>
 <!-- END: this line ends content for HTML phase 21 by: bin/pandoc-wrapper.sh via bin/md2html.sh -->
 <!-- START: this line starts content from: inc/after-content.default.html -->
 
+    </div>
+
 <!-- END: this line ends content from: inc/after-content.default.html -->
 <!-- START: this line starts content from: inc/end-rightcolumn.default.html -->
 
@@ -660,7 +680,7 @@ is directly under a <code>year</code> directory.</p>
 -->
 
 <div class="footer">
-  <h2><a name="copyright"></a>Copyright and CC BY-SA 4.0 License</h2>
+  <h2><div id="copyright">Copyright and CC BY-SA 4.0 License</div></h2>
   <p>All IOCCC content including this file and web page are:</p>
   <b>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Copyright &copy; 1984-2024 by Landon Curt Noll. <a href="https://creativecommons.org/faq/#what-does-some-rights-reserved-mean">Some Rights Reserved</a>.</b>
   <p>This work is licensed by Landon Curt Noll under:</p>