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/tbr/.entry.json

@@ -44,7 +44,7 @@
 	},
 	{
 	    "file_path" : "1990_tbr.tar.bz2",
-	    "inventory_order" : 100000,
+	    "inventory_order" : 1415926535,
 	    "OK_to_edit" : false,
 	    "display_as" : "tbz2",
 	    "display_via_github" : false,

1990/tbr/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 another version of this program. See the <a href="#alternate-code">alternate
 version</a> section below.</p>
 <h3 id="bugs-and-misfeatures">Bugs and (Mis)features:</h3>
@@ -155,7 +156,7 @@ version</a> section below.</p>
 <p>In 2023 it was noticed that in some systems like macOS there was confusing
 output due to a warning at runtime that was interspersed with the output of the
 program. For instance it would show:</p>
-<pre class="&lt;!---sh--&gt;"><code>    ./tbr
+<pre><code>    ./tbr
     $ warning: this program uses gets(), which is unsafe.</code></pre>
 <p>which kind of hid the prompt. Thus the entry was changed to use <code>fgets(3)</code> which
 is referred to later in this file.</p>
@@ -163,14 +164,14 @@ is referred to later in this file.</p>
 this entry would not compile in modern systems. This fix is also referred to
 below, in the <a href="#alternate-code">alternate version</a> section.</p>
 <h2 id="to-use">To use:</h2>
-<pre class="&lt;!---sh--&gt;"><code>    ./tbr
+<pre><code>    ./tbr
     $ enter some shell commands</code></pre>
 <p>NOTE: globs do not work with this entry. Why?</p>
 <p>NOTE: <code>exit</code> does not work and neither does <code>logout</code>. To exit try sending ctrl-d
 or ctrl-c (or kill it from another terminal :-) ). But why does it not work with
 just <code>exit</code> or <code>logout</code>? Hint: see the authors’ remarks.</p>
 <h2 id="try">Try:</h2>
-<pre class="&lt;!---sh--&gt;"><code>    ./tbr
+<pre><code>    ./tbr
     $ ls -l tbr tbr.c
 
     # notice how the following does not work:
@@ -187,7 +188,7 @@ documented, are not considered bugs as such in the context of the contest.</p>
 <h2 id="alternate-code">Alternate code:</h2>
 <p>The authors supplied us with a slightly smaller unformatted version
 of the program which we include below:</p>
-<pre class="&lt;!---c--&gt;"><code>    #define D ,close(
+<pre><code>    #define D ,close(
     char*c,q[512],m[256],*v[99],**u,*i[3];int f[2],p;main(){for(m[m[60]=m[62]=
     32]=m[*m=124[m]=9]=6;e(-8),gets(1+(c=q))||(exit(0),0);r(0,0))for(;*++c;);}
     r(t,o){*i=i[2]=0;for(u=v+98;m[*--c]^9;m[*c]&amp;32?i[*c&amp;2]=
@@ -201,9 +202,9 @@ of the program which we include below:</p>
 as well as the <code>gets()</code> to <code>fgets()</code> fix applied to it to make it functionally
 equivalent like the authors intended.</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>
-<pre class="&lt;!---sh--&gt;"><code>    ./tbr.alt</code></pre>
+<pre><code>    ./tbr.alt</code></pre>
 <h2 id="judges-remarks">Judges’ remarks:</h2>
 <p>This program touches on a well known Unix utility, the 6th edition Bourne Shell
 (<code>/bin/sh</code>), whose original source was considered to be extremely obfuscated by
@@ -245,9 +246,9 @@ is parsed; a pointer to the stack of arguments is assigned and an
 argument is stolen every time a <code>&gt;</code> or <code>&lt;</code> is encountered. The
 shell flags an error if no arguments are on the stack. Thus, for
 example:</p>
-<pre class="&lt;!---sh--&gt;"><code>    cat &gt; foo &gt; bar</code></pre>
+<pre><code>    cat &gt; foo &gt; bar</code></pre>
 <p>cats to <code>foo</code>, since it was pushed last, but</p>
-<pre class="&lt;!---sh--&gt;"><code>    cat &gt; &gt; foo bar</code></pre>
+<pre><code>    cat &gt; &gt; foo bar</code></pre>
 <p>cats to <code>bar</code>, since <code>bar</code> was pushed under <code>foo</code> (remember we’re
 parsing right-left).</p>
 <p>Depending on your flavor of Unix, <code>cd</code> without an argument will
@@ -281,10 +282,10 @@ all <code>ed(1)</code> does too.</p>
 <li><a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/1990/tbr/Makefile">Makefile</a> - entry Makefile</li>
 <li><a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/1990/tbr/tbr.alt.c">tbr.alt.c</a> - alternative source</li>
 <li><a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/1990/tbr/tbr.orig.c">tbr.orig.c</a> - original source</li>
-<li><a href="1990_tbr.tar.bz2">1990_tbr.tar.bz2</a> - download entry tarball</li>
 </ul>
 <h2 id="secondary-files">Secondary files</h2>
 <ul>
+<li><a href="1990_tbr.tar.bz2">1990_tbr.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/tbr/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/tbr/.entry.json">.entry.json</a> - description of entry in JSON</li>