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.

1990/theorem/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>
@@ -141,13 +142,13 @@ Location: <a href="../../location.html#US">US</a> - <em>United States of America
 <!-- 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 all</code></pre>
+<pre><code>    make all</code></pre>
 <h3 id="bugs-and-misfeatures">Bugs and (Mis)features:</h3>
 <p>The current status of this entry is:</p>
 <pre><code>    STATUS: INABIAF - please **DO NOT** fix</code></pre>
 <p>For more detailed information see <a href="../../bugs.html#1990_theorem">1990 theorem bugs</a>.</p>
 <h2 id="to-use">To use:</h2>
-<pre class="&lt;!---sh--&gt;"><code>    ./theorem expression x1 x2 h y1</code></pre>
+<pre><code>    ./theorem expression x1 x2 h y1</code></pre>
 <p>where:</p>
 <pre><code>    expression - function f(x,y)  (see below)
     x1 - start of interval
@@ -155,7 +156,7 @@ Location: <a href="../../location.html#US">US</a> - <em>United States of America
     h - step size
     y1 - initial value  (y(x1) == y1)</code></pre>
 <h2 id="try">Try:</h2>
-<pre class="&lt;!---sh--&gt;"><code>    ./try.sh</code></pre>
+<pre><code>    ./try.sh</code></pre>
 <h2 id="judges-remarks">Judges’ remarks:</h2>
 <p>The program’s source implements four functions, all from the
 same source file!</p>
@@ -169,23 +170,23 @@ operators:</p>
 integer powers. Also note that all expressions are evaluated strictly
 left to right. (i.e., parenthesis aren’t supported).</p>
 <p>Try running the program with the following args:</p>
-<pre class="&lt;!---sh--&gt;"><code>    ./theorem y 0 1 0.1 1
+<pre><code>    ./theorem y 0 1 0.1 1
     ./theorem 1/x 1 2 0.1 0
     ./theorem &#39;x^2/y+x&#39; 0 1 0.1 6</code></pre>
 <p>But wait, there is more! You also get, free of charge, a
 reversing filter! Try:</p>
-<pre class="&lt;!---sh--&gt;"><code>    ./theorem -r 0 0 0 0 &lt; theorem.c &gt; sorter.c</code></pre>
+<pre><code>    ./theorem -r 0 0 0 0 &lt; theorem.c &gt; sorter.c</code></pre>
 <p>Still not impressed? The author throws in for free, a
 sort program! Try:</p>
-<pre class="&lt;!---sh--&gt;"><code>    make sorter
+<pre><code>    make sorter
     ls | ./sorter</code></pre>
 <p>This program is safe for home use as well. The author has
 included a safety feature in case you misplace the original
 program source:</p>
-<pre class="&lt;!---sh--&gt;"><code>    ./sorter -r 0 0 0 0 &lt; sorter.c &gt; theorem_bkp.c</code></pre>
+<pre><code>    ./sorter -r 0 0 0 0 &lt; sorter.c &gt; theorem_bkp.c</code></pre>
 <p>And finally, as a special offer to users of this entry,
 the author provides a Fibonacci sequence generator! Try:</p>
-<pre class="&lt;!---sh--&gt;"><code>    ./sorter 0 0 0 0 &lt; theorem.c &gt; fibonacci.c
+<pre><code>    ./sorter 0 0 0 0 &lt; theorem.c &gt; fibonacci.c
     make fibonacci
     ./fibonacci 1 1
     ./fibonacci 2 1</code></pre>
@@ -233,10 +234,10 @@ lines, each less than 99 characters long.</p>
 <li><a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/1990/theorem/Makefile">Makefile</a> - entry Makefile</li>
 <li><a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/1990/theorem/theorem.orig.c">theorem.orig.c</a> - original source</li>
 <li><a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/1990/theorem/try.sh">try.sh</a> - how to run</li>
-<li><a href="1990_theorem.tar.bz2">1990_theorem.tar.bz2</a> - download entry tarball</li>
 </ul>
 <h2 id="secondary-files">Secondary files</h2>
 <ul>
+<li><a href="1990_theorem.tar.bz2">1990_theorem.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/1990/theorem/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/1990/theorem/.entry.json">.entry.json</a> - description of entry in JSON</li>