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`.

1987/index.html

@@ -163,18 +163,16 @@ Entries of 1987 - The 4th IOCCC</h1>
 <p><strong>Download IOCCC</strong> <a
 href="1987/ioccc.1987.tar.bz2">1987 entry source</a></p>
 <ul>
-<li><a href="1987/biggar/index.html">1987/biggar</a> - Best Abuse of the
+<li><a href="biggar/index.html">1987/biggar</a> - Best Abuse of the
 Rules</li>
-<li><a href="1987/heckbert/index.html">1987/heckbert</a> - Best
-Obfuscator of Programs</li>
-<li><a href="1987/hines/index.html">1987/hines</a> - Worst Style</li>
-<li><a href="1987/korn/index.html">1987/korn</a> - Best One Liner</li>
-<li><a href="1987/lievaart/index.html">1987/lievaart</a> - Grand
-Prize</li>
-<li><a href="1987/wall/index.html">1987/wall</a> - Most Useful
+<li><a href="heckbert/index.html">1987/heckbert</a> - Best Obfuscator of
+Programs</li>
+<li><a href="hines/index.html">1987/hines</a> - Worst Style</li>
+<li><a href="korn/index.html">1987/korn</a> - Best One Liner</li>
+<li><a href="lievaart/index.html">1987/lievaart</a> - Grand Prize</li>
+<li><a href="wall/index.html">1987/wall</a> - Most Useful
 Obfuscation</li>
-<li><a href="1987/westley/index.html">1987/westley</a> - Best
-Layout</li>
+<li><a href="westley/index.html">1987/westley</a> - Best Layout</li>
 </ul>
 <p> <strong>Jump to:</strong> <a href="#">top</a></p>