fix IOCCC rules and guidelines web pages

Fix the Nu html check URL for `next/rules.html` and `next/guidelines.html`.

Restore building `next/rules.html` and `next/guidelines.html` by
`bin/gen-top-html.sh` and `make gen_top_html`.  Also `make gen_status`
will rebuild these files if `status.json` changes or `news.html`
was modified.

Add cross links between  `next/rules.html` and `next/guidelines.html`.

Changed `bin/gen-top-html.sh` VERSION from "1.4.3 2024-04-21"
to "1.4.4 2024-04-21".

Ran `make gen_top_html gen_status` to perform the above.

next/guidelines.md

@@ -34,6 +34,8 @@ writing from the contest judges.
 
 **`|`** This guidelines file is version **2023-04-04-v28**.
 
+**IMPORTANT**: Be sure to read the [IOCCC rules](rules.html).
+
 
 ### Change marks