add rules, guidelines, fix HTML code, move compressed tarball in inventory

By changing the _inventory_order_ of the compressed tarball from
**100000** to **1415926535**, the compressed tarball will land at
the top of the secondary file list and remain still easy to find.

Updated the `manifest.numbers` spreadsheet and rebuilt
the `.entry.json` files.

Added `next/` directory to hold the next IOCCC rules and guidelines.
Added `next/README.md` that `bin/gen-top-html.sh` uses to form
the `next/index.html` file.

Added _Rules and Guidelines_ link to the sidenav bar to link to the
`next/index.html` file.

Added _IOCCC Rules_ as `next/rules.md` that `bin/gen-top-html.sh`
uses to form the `next/rules.html` file.

Added _IOCCC Guidelines_ as `next/guidelines.md` that `bin/gen-top-html.sh`
uses to form the `next/guidelines.html` file.

Changed `bin/gen-top-html.sh` VERSION from "1.2.4 2024-04-13"
to "1.3 2024-04-14".

Prevent `pandoc(1)` from interpreting the commented out language
of a markdown code block as a code class.  So a markdown such as:

````
``` <!---sh-->
...
```
````

that produced HTML of the form:

```html
<pre class="&lt;!---sh--&gt;"><code>...</code></pre>
```

will now produce HTML of the form:

```html
<pre><code>...</code></pre>
```

NOTE: Before when the language of a markdown code block
was not commented, the HTML produced by `pandoc(1)` was
oddly indented with extra whitespace on the first line
of the code block.  While commenting out the language
of the code block removed some of the odd intending,
it left a weird class in the HTML pre block that
surrounded the HTML code block.  This hack prevents
`pandoc(1)` from assigning a class to the HTML pre block.

Changed `in/md2html.sh` VERSION from "1.2.1 2024-04-13"
to "1.3 2024-04-14".

Added `make gen_sitemap` to end of both `make www` and `make
quick_www` in top level Makefile.

Ram `make www` to test under macOS and to perform the above.

**IMPORTANT NOTE**: The current `next/rules.md` and `next/guidelines.md`
are simply the 2020 IOCCC Rules and Guidelines converted into
markdown form.  There are **NOT** the Rules and Guidelines that
will be used the IOCCC MOCK, nor the next IOCCC.

TODO: Improve the `bin/gen-status.sh` tool to modify the top of the
      `next/rules.md` and `next/guidelines.md` files to keep them
      in sync with the _contest_status_ as found in `status.json`.

TODO: Improve the look and feel of the `next/rules.md` and
      `next/guidelines.md` markdown files.

1993/plummer/index.html

@@ -88,6 +88,7 @@
     <div class="sidenav">
       <a href="../../news.html">IOCCC News</a>
       <a href="../../status.html">Contest status</a>
+      <a href="../../next/index.html">Rules and Guidelines</a>
       <a href="../../faq.html#submit">How to enter the IOCCC</a>
       <a href="../../faq.html">FAQ</a>
     </div>
@@ -141,19 +142,19 @@ Location: <a href="../../location.html#ZZ">ZZ</a> - <em>Unknown location</em></l
 <!-- START: this line starts content for HTML phase 21 by: bin/pandoc-wrapper.sh via bin/md2html.sh -->
 
 <h2 id="to-build">To build:</h2>
-<pre class="&lt;!---sh--&gt;"><code>    make alt</code></pre>
+<pre><code>    make alt</code></pre>
 <p>We recommend that you try the alternate version first to get a better idea of
 what this entry looked like back in 1993. The alternate version sleeps (via
 <code>usleep(3)</code>) in between writes, defaulting at 1000 microseconds (but
 reconfigurable). If you wish to see the original entry then see <a href="#original-code">original
 code</a> below.</p>
 <p>If you wish to speed the entry up, say to 500 microseconds between writes, try:</p>
-<pre class="&lt;!---sh--&gt;"><code>    make clobber SLEEP=500 alt</code></pre>
+<pre><code>    make clobber SLEEP=500 alt</code></pre>
 <p>Alternatively if you wish to slow it down, say to 1500 microseconds between
 writes, try:</p>
-<pre class="&lt;!---sh--&gt;"><code>    make clobber SLEEP=1500 alt</code></pre>
+<pre><code>    make clobber SLEEP=1500 alt</code></pre>
 <h2 id="to-use">To use:</h2>
-<pre class="&lt;!---sh--&gt;"><code>    ./plummer.alt number arg</code></pre>
+<pre><code>    ./plummer.alt number arg</code></pre>
 <p>where:</p>
 <ul>
 <li>number is a number (try 21701)</li>
@@ -163,7 +164,7 @@ writes, try:</p>
 <a href="https://hitchhikers.fandom.com/wiki/Vogon">Vogons</a> build that <a href="https://hitchhikers.fandom.com/wiki/Bypass">hyperspace
 bypass</a>.</p>
 <h2 id="try">Try:</h2>
-<pre class="&lt;!---sh--&gt;"><code>    ./try.alt.sh
+<pre><code>    ./try.alt.sh
 
     ./try.alt.sh 21701
 
@@ -183,11 +184,11 @@ bypass</a>.</p>
 faster (depending on the <code>SLEEP</code> parameter specified in the build of <code>alt</code>, of
 course).</p>
 <h3 id="original-build">Original build:</h3>
-<pre class="&lt;!---sh--&gt;"><code>    make all</code></pre>
+<pre><code>    make all</code></pre>
 <h3 id="original-use">Original use:</h3>
 <p>Use <code>plummer</code> as you would <code>plummer.alt</code> above.</p>
 <h3 id="original-try">Original try:</h3>
-<pre class="&lt;!---sh--&gt;"><code>    ./try.sh
+<pre><code>    ./try.sh
 
     ./try.sh 21701
 
@@ -281,10 +282,10 @@ successively larger number to the end of a string.</p>
 <li><a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/1993/plummer/plummer.orig.c">plummer.orig.c</a> - original source</li>
 <li><a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/1993/plummer/try.alt.sh">try.alt.sh</a> - how to run alternative code</li>
 <li><a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/1993/plummer/try.sh">try.sh</a> - how to run</li>
-<li><a href="1993_plummer.tar.bz2">1993_plummer.tar.bz2</a> - download entry tarball</li>
 </ul>
 <h2 id="secondary-files">Secondary files</h2>
 <ul>
+<li><a href="1993_plummer.tar.bz2">1993_plummer.tar.bz2</a> - download entry tarball</li>
 <li><a href="index.html">index.html</a> - this web page</li>
 <li><a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/1993/plummer/README.md">README.md</a> - markdown source for this web page</li>
 <li><a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/1993/plummer/.entry.json">.entry.json</a> - description of entry in JSON</li>