In a few cases, the error message related to a file or directory
test was corrected.
Changed `bin/gen-sitemap.sh` VERSION from "1.3.6 2024-04-13"
to "1.3.7 2024-04-14".
Changed `bin/gen-year-index.sh` VERSION from "1.0.6 2024-04-13"
to "1.0.7 2024-04-14".
Changed `bin/untar-year.sh` VERSION from "1.0.1 2024-04-13"
to "1.0.2 2024-04-14".
Updated `bin/gen-status.sh` to change the header of `next/guidelines.md`
and `next/rules.md` to match the _contest_status_ in `status.json`.
Moved `make gen_top_html` after `make gen_status` in `make www`
and in `make quick_www` rules in the top Makefile.
Changed `bin/gen-status.sh` VERSION from "1.2.1 2024-04-13"
to "1.3 2024-04-14".
Fixed the DESCRIPTION for `next/guidelines.html`.
Run `make www` to perform the above and test under macOS.
