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.

2020/ferguson1/COMPILING.html

@@ -83,6 +83,7 @@
     <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>
@@ -146,7 +147,7 @@ matters; I only have Intel CPUs and arm64 (MacBook Pro M1).</p>
 <p>I imagine that it works for 32-bit systems but I do not know for sure.</p>
 <h1 id="portability-macos">Portability: macOS</h1>
 <p>You should be able to get the compiler with:</p>
-<pre class="&lt;!---sh--&gt;"><code>    sudo xcode-select --install</code></pre>
+<pre><code>    sudo xcode-select --install</code></pre>
 <p>You don’t need Xcode itself and it appears that the command line tools (as above
 should install) already has ncurses so there shouldn’t be anything else that
 needs to be done. But I’m not actually sure of this - I’m seeing conflicting
@@ -159,20 +160,20 @@ so that you don’t need sudo because … Well never mind.</p>
 you want to use the Makefile) to compile and link this entry. With Fedora more
 recent versions there’s the <code>dnf</code> package manager but I cannot help with any of
 the GUI installers since I don’t use them. Something like:</p>
-<pre class="&lt;!---sh--&gt;"><code>    sudo dnf install ncurses-devel ncurses make gcc</code></pre>
+<pre><code>    sudo dnf install ncurses-devel ncurses make gcc</code></pre>
 <p>or</p>
-<pre class="&lt;!---sh--&gt;"><code>    # dnf install ncurses-devel ncurses make gcc</code></pre>
+<pre><code>    # dnf install ncurses-devel ncurses make gcc</code></pre>
 <h1 id="portability-centos">Portability: CentOS</h1>
 <p>Just like Fedora you will need <code>gcc</code>, <code>ncurses</code>, <code>ncurses-devel</code> (and if you
 want to use the Makefile <code>make</code>). CentOS uses <code>yum</code> and CentOS 8 uses <code>dnf</code>.
 So:</p>
-<pre class="&lt;!---sh--&gt;"><code>    sudo yum install ncurses-devel ncurses make gcc</code></pre>
+<pre><code>    sudo yum install ncurses-devel ncurses make gcc</code></pre>
 <p>or</p>
-<pre class="&lt;!---sh--&gt;"><code>    # yum install ncurses-devel ncurses make gcc</code></pre>
+<pre><code>    # yum install ncurses-devel ncurses make gcc</code></pre>
 <p>or</p>
-<pre class="&lt;!---sh--&gt;"><code>    sudo dnf install ncurses-devel ncurses make gcc</code></pre>
+<pre><code>    sudo dnf install ncurses-devel ncurses make gcc</code></pre>
 <p>or</p>
-<pre class="&lt;!---sh--&gt;"><code>    # dnf install ncurses-devel ncurses make gcc</code></pre>
+<pre><code>    # dnf install ncurses-devel ncurses make gcc</code></pre>
 <p>You can also use clang to compile (which is what gcc actually is under macOS).</p>
 <h1 id="compilation-notes">Compilation notes</h1>
 <p>As long as you have the dependencies above the only thing that comes to mind is