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.

1995/vanschnitz/.entry.json

@@ -52,7 +52,7 @@
 	},
 	{
 	    "file_path" : "1995_vanschnitz.tar.bz2",
-	    "inventory_order" : 100000,
+	    "inventory_order" : 1415926535,
 	    "OK_to_edit" : false,
 	    "display_as" : "tbz2",
 	    "display_via_github" : false,

1995/vanschnitz/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>
@@ -144,7 +145,7 @@ 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 all</code></pre>
+<pre><code>    make all</code></pre>
 <p>The authors provided a spoiler version, originally uuencoded but uudecoded by us
 in 2023. See <a href="#alternate-code">Alternate code</a> below.</p>
 <h3 id="bugs-and-misfeatures">Bugs and (Mis)features:</h3>
@@ -152,16 +153,16 @@ in 2023. See <a href="#alternate-code">Alternate code</a> below.</p>
 <pre><code>    STATUS: missing file - please provide it</code></pre>
 <p>For more detailed information see <a href="../../bugs.html#1995_vanschnitz">1995 vanschnitz bugs</a>.</p>
 <h2 id="to-use">To use:</h2>
-<pre class="&lt;!---sh--&gt;"><code>    ./vanschnitz</code></pre>
+<pre><code>    ./vanschnitz</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="alternate-code">Alternate code:</h2>
 <p>The authors provided a spoiler version of the program. Originally uuencoded we
 have decoded it for the wider audience in <a href="vanschnitz.alt.c">vanschnitz.alt.c</a>. The
 <code>uuencode</code>d blob is still available in their remarks below. They encourage you
 to first try and figure out the program without the spoiler.</p>
 <h3 id="alternate-build">Alternate build:</h3>
-<pre class="&lt;!---sh--&gt;"><code>    make alt</code></pre>
+<pre><code>    make alt</code></pre>
 <h3 id="alternate-use">Alternate use:</h3>
 <p>Use <code>vanschnitz.alt</code> as you would <code>vanschnitz</code> above.</p>
 <h2 id="judges-remarks">Judges’ remarks:</h2>
@@ -187,7 +188,7 @@ for. This is done by defining the symbol <code>n</code> on the compile
 line. For instance, to cause the compiler to solve the Towers
 of Hanoi problem with four disks, you would compile the program
 like this:</p>
-<pre class="&lt;!---sh--&gt;"><code>    gcc hanoi.c -o hanoi -Dn=4</code></pre>
+<pre><code>    gcc hanoi.c -o hanoi -Dn=4</code></pre>
 <p>A default value of <code>5</code> will be used for <code>n</code> if you do not define
 it on the command line. The value of <code>n</code> cannot be greater than
 fifteen (the compiler we used to test has a limit on the <code>#include</code>
@@ -208,7 +209,7 @@ ANSI C feature in which adjacent character strings are
 concatenated; a version that does not use this feature has been
 included for people who can only run K&amp;R). A good way to see
 the resulting program (on a Unix system) is to do the command</p>
-<pre class="&lt;!---sh--&gt;"><code>    gcc hanoi.c -E -Dn=5 | grep -v \# | grep -v ^\$</code></pre>
+<pre><code>    gcc hanoi.c -E -Dn=5 | grep -v \# | grep -v ^\$</code></pre>
 <p>For an odd number of disks, the program will provide a
 solution wherein the disks end up on peg 2; for an even
 number of disks, they will end on peg 3. This should
@@ -321,10 +322,10 @@ to try to decipher the program without it…</p>
 <li><a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/1995/vanschnitz/vanschnitz.alt.c">vanschnitz.alt.c</a> - alternative source</li>
 <li><a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/1995/vanschnitz/vanschnitz.orig.c">vanschnitz.orig.c</a> - original source</li>
 <li><a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/1995/vanschnitz/try.sh">try.sh</a> - how to run</li>
-<li><a href="1995_vanschnitz.tar.bz2">1995_vanschnitz.tar.bz2</a> - download entry tarball</li>
 </ul>
 <h2 id="secondary-files">Secondary files</h2>
 <ul>
+<li><a href="1995_vanschnitz.tar.bz2">1995_vanschnitz.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/1995/vanschnitz/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/1995/vanschnitz/.entry.json">.entry.json</a> - description of entry in JSON</li>