change inventory layout for year level index.html files

The "Jump to top" in the inventory section of an entry index.html file
now is below the secondary file list, with a short line above it.

Changed `bin/output-year-index.sh` VERSION from "1.3 2024-04-15"
to "1.4 2024-04-21".

Run `make gen_year_index` to perform the above.

1995/index.html

@@ -282,7 +282,10 @@ Dessert: Key lime pie</p>
 <li><a href="spinellis/index.html">1995/spinellis</a> - Abusing The Rules</li>
 <li><a href="vanschnitz/index.html">1995/vanschnitz</a> - Worst Abuse of the C Preprocessor and Most Likely to Amaze</li>
 </ul>
-<p> <strong>Jump to:</strong> <a href="#">top</a></p>
+<hr style="width:10%;text-align:left;margin-left:0">
+<h4>
+Jump to: <a href="#">top</a>
+</h4>
 
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