Convert internals documentation to Markdown

2025-06-30 08:54:39 Peter Eisentraut (petere) Closed in commitfest 2025-01 with status: Returned with feedback 2024-12-10 06:28:32 Michael Paquier (michael-kun) Closed in commitfest 2024-11 with status: Moved to next CF 2024-12-02 09:02:54 Peter Eisentraut (petere) New status: Ready for Committer 2024-10-03 11:43:27 Peter Eisentraut (petere) Closed in commitfest 2024-09 with status: Moved to next CF 2024-08-01 04:06:07 Corey Huinker (coreyh) Closed in commitfest 2024-07 with status: Moved to next CF 2024-05-12 16:01:57 Peter Eisentraut (petere) Added petere as reviewer 2024-04-09 08:19:53 Daniel Gustafsson (d_gustafsson) Changed authors to Daniel Gustafsson (d_gustafsson) 2024-04-09 08:19:53 Daniel Gustafsson (d_gustafsson) Changed targetversion to 18 2024-04-09 08:19:53 Daniel Gustafsson (d_gustafsson) Changed gitlink to https://github.com/danielgustafsson/postgres/tree/markdown 2024-04-09 08:19:30 Daniel Gustafsson (d_gustafsson) Attached mail thread 950C832E-DE66-4D8C-A2EA-5B24ABEBB115@yesql.se 2024-04-09 08:19:29 Daniel Gustafsson (d_gustafsson) Created patch record