Convert old Minecraft maps to latest version

I had an old map from the alpha/beta release of Minecraft Java Edition I wanted to convert so I could play it with a modern Minecraft version (1.21.10 as of writing), but to convert such a map it needs to be done in steps. Infdev introduced the Alpha level format , and it was the level format up until beta 1.2. Beta 1.3 introduced the Region file format until release 1.2 which introduced the Anvil…