build missing HTML files for entries

Setup a simple topnav for missing HTML files for entries.

Added `bin/gen-other-html.sh` to build entry HTML files from
markdown other than README.md to index.html HTML files.

Fixed duplicate link text in `2020/ferguson1/gameplay.md`.

Improved `inc/md2html.cfg` to support building the missing HTML
files for entries.

Added `make gen_other_html` to top level Makefile.
Added `make gen_other_html` to `make quick_www` and `make www`.

Fixed inventory links for year level index.html files.
Changed `bin/output-year-index.sh` VERSION from "1.0.1 2024-02-23"
to "1.1 2024-02-27".

Added missing lines in `manifest.numbers`.  Update the affected
`.entry.json` files.

The manifest (in both `manifest.numbers` and the collection of
manifests from of all entry `.entry.json` files) now match.  Errors
from `make verify_entry_files` will now abort both `make quick_www`
and `make www` rules in the top level `Makefile`.

Changed markdown files in manifest to have an _inventory_order_ of
_2000000000_ so that the `index.html` file will usually appear at
the start of the _Secondary files_ set for the "#inventory" section
of an entry's `index.html` file.

Changed compressed tar files (files that end in _.tar.bz2_) in
manifest to have an _inventory_order_ of _100000_ so that these
files will usually appear at the end of the _Primary files_ set for
the "#inventory" section of an entry's `index.html` file.

Added 'Jump to top` link above the _Primary files_ section.
Changed `bin/output-index-inventory.sh` VERSION from "1.1.1 2024-02-23"
to "1.2 2024-02-27".

Updated HTML files to perform the above via `make www`.

2000/index.html

@@ -209,31 +209,30 @@ Entries of 2000 - The 15th IOCCC</h1>
 <p><strong>Download IOCCC</strong> <a
 href="2000/ioccc.2000.tar.bz2">2000 entry source</a></p>
 <ul>
-<li><a href="2000/anderson/index.html">2000/anderson</a> - Best Use of
+<li><a href="anderson/index.html">2000/anderson</a> - Best Use of
 Flags</li>
-<li><a href="2000/bellard/index.html">2000/bellard</a> - Most Specific
+<li><a href="bellard/index.html">2000/bellard</a> - Most Specific
 Output</li>
-<li><a href="2000/bmeyer/index.html">2000/bmeyer</a> - Best Utility</li>
-<li><a href="2000/briddlebane/index.html">2000/briddlebane</a> - Best
-Abuse of User</li>
-<li><a href="2000/dhyang/index.html">2000/dhyang</a> - Best Layout</li>
-<li><a href="2000/dlowe/index.html">2000/dlowe</a> - Worst Abuse of the
+<li><a href="bmeyer/index.html">2000/bmeyer</a> - Best Utility</li>
+<li><a href="briddlebane/index.html">2000/briddlebane</a> - Best Abuse
+of User</li>
+<li><a href="dhyang/index.html">2000/dhyang</a> - Best Layout</li>
+<li><a href="dlowe/index.html">2000/dlowe</a> - Worst Abuse of the
 Rules</li>
-<li><a href="2000/jarijyrki/index.html">2000/jarijyrki</a> - Best of
+<li><a href="jarijyrki/index.html">2000/jarijyrki</a> - Best of
 Show</li>
-<li><a href="2000/natori/index.html">2000/natori</a> - Best Small
+<li><a href="natori/index.html">2000/natori</a> - Best Small
 Program</li>
-<li><a href="2000/primenum/index.html">2000/primenum</a> - Best Abuse of
+<li><a href="primenum/index.html">2000/primenum</a> - Best Abuse of
 CPP</li>
-<li><a href="2000/rince/index.html">2000/rince</a> - Astronomically
+<li><a href="rince/index.html">2000/rince</a> - Astronomically
 Obfuscated</li>
-<li><a href="2000/robison/index.html">2000/robison</a> - Best game</li>
-<li><a href="2000/schneiderwent/index.html">2000/schneiderwent</a> -
-Most Timely Output</li>
-<li><a href="2000/thadgavin/index.html">2000/thadgavin</a> - Most
-Portable Output</li>
-<li><a href="2000/tomx/index.html">2000/tomx</a> - Most Complete
-Program</li>
+<li><a href="robison/index.html">2000/robison</a> - Best game</li>
+<li><a href="schneiderwent/index.html">2000/schneiderwent</a> - Most
+Timely Output</li>
+<li><a href="thadgavin/index.html">2000/thadgavin</a> - Most Portable
+Output</li>
+<li><a href="tomx/index.html">2000/tomx</a> - Most Complete Program</li>
 </ul>
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