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`.

2018/index.html

@@ -207,32 +207,29 @@ Entries of 2018 - The 25th IOCCC</h1>
 <p><strong>Download IOCCC</strong> <a
 href="2018/ioccc.2018.tar.bz2">2018 entry source</a></p>
 <ul>
-<li><a href="2018/algmyr/index.html">2018/algmyr</a> - Most
-cacophonic</li>
-<li><a href="2018/anderson/index.html">2018/anderson</a> - Most able to
+<li><a href="algmyr/index.html">2018/algmyr</a> - Most cacophonic</li>
+<li><a href="anderson/index.html">2018/anderson</a> - Most able to
 divine code gaps</li>
-<li><a href="2018/bellard/index.html">2018/bellard</a> - Most
+<li><a href="bellard/index.html">2018/bellard</a> - Most
 inflationary</li>
-<li><a href="2018/burton1/index.html">2018/burton1</a> - Best
-one-liner</li>
-<li><a href="2018/burton2/index.html">2018/burton2</a> - Best abuse of
-the rules</li>
-<li><a href="2018/ciura/index.html">2018/ciura</a> - Most likely to be
+<li><a href="burton1/index.html">2018/burton1</a> - Best one-liner</li>
+<li><a href="burton2/index.html">2018/burton2</a> - Best abuse of the
+rules</li>
+<li><a href="ciura/index.html">2018/ciura</a> - Most likely to be
 awarded</li>
-<li><a href="2018/endoh1/index.html">2018/endoh1</a> - Best tool to
-reveal holes</li>
-<li><a href="2018/endoh2/index.html">2018/endoh2</a> - Best use of
+<li><a href="endoh1/index.html">2018/endoh1</a> - Best tool to reveal
+holes</li>
+<li><a href="endoh2/index.html">2018/endoh2</a> - Best use of
 python</li>
-<li><a href="2018/ferguson/index.html">2018/ferguson</a> - Best use of
-weasel words</li>
-<li><a href="2018/giles/index.html">2018/giles</a> - Most unstable</li>
-<li><a href="2018/hou/index.html">2018/hou</a> - Most likely to top the
+<li><a href="ferguson/index.html">2018/ferguson</a> - Best use of weasel
+words</li>
+<li><a href="giles/index.html">2018/giles</a> - Most unstable</li>
+<li><a href="hou/index.html">2018/hou</a> - Most likely to top the
 charts</li>
-<li><a href="2018/mills/index.html">2018/mills</a> - Best of show</li>
-<li><a href="2018/poikola/index.html">2018/poikola</a> - Most
-stellar</li>
-<li><a href="2018/vokes/index.html">2018/vokes</a> - Most connected</li>
-<li><a href="2018/yang/index.html">2018/yang</a> - Most shifty</li>
+<li><a href="mills/index.html">2018/mills</a> - Best of show</li>
+<li><a href="poikola/index.html">2018/poikola</a> - Most stellar</li>
+<li><a href="vokes/index.html">2018/vokes</a> - Most connected</li>
+<li><a href="yang/index.html">2018/yang</a> - Most shifty</li>
 </ul>
 <p> <strong>Jump to:</strong> <a href="#">top</a></p>