Support region and playerdata files

[FederAndInk]

I don't know if it is the scope of this library, but it would be great to support region files (.mca) and playerdata files :)

[DanDucky]

Currently working on a project that uses .mca files, if you want to convert them within your program you can use this: https://github.com/HubTou/MCA2NBT

From my experience the code in that repo needed a bit of editing but it works well enough :)

[Ktlo]

Region files are definitely out of the scope of this library. Player data files should work, I think.