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`.

1989/paul/index.html

@@ -244,9 +244,9 @@ https://creativecommons.org/licenses/by-sa/4.0/</p>
 
 <h1 id="inventory-for-1989paul"><a name="inventory"></a>Inventory for
 1989/paul</h1>
+<p><a href="#top">Jump to top</a></p>
 <h2 id="primary-files">Primary files</h2>
 <ul>
-<li><a href="index.html">index.html</a> - entry home page</li>
 <li><a
 href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/1989/paul/paul.c">paul.c</a>
 - entry source</li>
@@ -264,6 +264,7 @@ source</li>
 </ul>
 <h2 id="secondary-files">Secondary files</h2>
 <ul>
+<li><a href="index.html">index.html</a> - entry home page</li>
 <li><a
 href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/1989/paul/.entry.json">.entry.json</a>
 - description of entry in JSON</li>