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.

2011/index.html

@@ -182,7 +182,7 @@ See also <a href="../faq.html">the IOCCC FAQ</a> for addition information on the
 <!-- START: this line starts content generated by: bin/output-year-index.sh -->
 
 <h1 id="winning-entries-of-2011---the-20th-ioccc"><a name=inventory></a><a name=2011></a>Winning Entries of 2011 - The 20th IOCCC</h1>
-<p><strong>Download IOCCC</strong> <a href="2011/ioccc.2011.tar.bz2">2011 entry source</a></p>
+<p><strong>Download</strong> all <a href="2011/2011.tar.bz2">2011 IOCCC entry source</a></p>
 <ul>
 <li><a href="akari/index.html">2011/akari</a> - Best of Show - Most Shrinkable</li>
 <li><a href="blakely/index.html">2011/blakely</a> - Most devolving</li>