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`.

1990/index.html

@@ -160,25 +160,22 @@ Entries of 1990 - The 7th IOCCC</h1>
 <p><strong>Download IOCCC</strong> <a
 href="1990/ioccc.1990.tar.bz2">1990 entry source</a></p>
 <ul>
-<li><a href="1990/baruch/index.html">1990/baruch</a> - Best Small
+<li><a href="baruch/index.html">1990/baruch</a> - Best Small
 Program</li>
-<li><a href="1990/cmills/index.html">1990/cmills</a> - Best Game</li>
-<li><a href="1990/dds/index.html">1990/dds</a> - Best Language Tool</li>
-<li><a href="1990/dg/index.html">1990/dg</a> - Best Abuse of the C
+<li><a href="cmills/index.html">1990/cmills</a> - Best Game</li>
+<li><a href="dds/index.html">1990/dds</a> - Best Language Tool</li>
+<li><a href="dg/index.html">1990/dg</a> - Best Abuse of the C
 Preprocessor</li>
-<li><a href="1990/jaw/index.html">1990/jaw</a> - Best
-Entropy-reducer</li>
-<li><a href="1990/pjr/index.html">1990/pjr</a> - Most Unusual Data
+<li><a href="jaw/index.html">1990/jaw</a> - Best Entropy-reducer</li>
+<li><a href="pjr/index.html">1990/pjr</a> - Most Unusual Data
 Structure</li>
-<li><a href="1990/scjones/index.html">1990/scjones</a> - ANSI
-Committee’s Worst Abuse of C</li>
-<li><a href="1990/stig/index.html">1990/stig</a> - Strangest Abuse of
-the Rules</li>
-<li><a href="1990/tbr/index.html">1990/tbr</a> - Best Utility</li>
-<li><a href="1990/theorem/index.html">1990/theorem</a> - Best of
-Show</li>
-<li><a href="1990/westley/index.html">1990/westley</a> - Best
-Layout</li>
+<li><a href="scjones/index.html">1990/scjones</a> - ANSI Committee’s
+Worst Abuse of C</li>
+<li><a href="stig/index.html">1990/stig</a> - Strangest Abuse of the
+Rules</li>
+<li><a href="tbr/index.html">1990/tbr</a> - Best Utility</li>
+<li><a href="theorem/index.html">1990/theorem</a> - Best of Show</li>
+<li><a href="westley/index.html">1990/westley</a> - Best Layout</li>
 </ul>
 <p> <strong>Jump to:</strong> <a href="#">top</a></p>