improve years.html and fix links to year-level compressed tarballs

Fixed links to year level compressed tarballs.

Added an "Inventory" of year-level compressed tarballs to the
generated `years.html` web page.

In `bin/gen-years.sh` changed VERSION from "1.0.3 2024-03-26"
to "1.1 2024-03-30".

In `bin/output-year-index.sh` changed VERSION from "1.1.2 2024-03-26"
to "1.2 2024-03-30".

Added `inc/topnav.empty.html` for an empty narrow topnav bar.

Changed references from "topnav=." to "topnav=empty" in `inc/md2html.cfg`.

Removed top level `ioccc.tar.bz2` compressed tarball.  NOTE: Sorry
(tm Canada 🇨🇦) to remove the top level `ioccc.tar.bz2` file.  We
will look into [Git Large File Storage [Git-LFS](https://git-lfs.com/).
If Git-LFS works well and does not have undesirable side effects,
we will consider restoring `ioccc.tar.bz2`.

Removed top level Makefile rules for "untar_all_tarball" and
"form_all_tarball".  Removed `bin/tar-all.sh`.

Added `make gen_status` to `make quick_www` and `make www` in the
top level `Makefile`.

Ran `make www` to perform the above and test under macOS.

1993/index.html

@@ -187,7 +187,7 @@ to serve as official taste testers. And as usual, the food was excellent.</p>
 <!-- START: this line starts content generated by: bin/output-year-index.sh -->
 
 <h1 id="winning-entries-of-1993---the-10th-ioccc"><a name=inventory></a><a name=1993></a>Winning Entries of 1993 - The 10th IOCCC</h1>
-<p><strong>Download IOCCC</strong> <a href="1993/ioccc.1993.tar.bz2">1993 entry source</a></p>
+<p><strong>Download</strong> all <a href="1993/1993.tar.bz2">1993 IOCCC entry source</a></p>
 <ul>
 <li><a href="ant/index.html">1993/ant</a> - Best Utility</li>
 <li><a href="cmills/index.html">1993/cmills</a> - Bill Gates Award</li>