Update Luanti (formerly Minetest) standard to 5.10.0

[appgurueu]

Minetest has been renamed to Luanti with the release of version 5.10.0.

This updates the standard to reflect that: It is now called luanti (with minetest still supported for compatibility). Most importantly, we now recommend using the core instead of the minetest namespace in code, though the latter is still being supported for an indefinite amount of time. (The core namespace alias has essentially always worked, but was only used internally and undocumented until now.)

It also updates the standard to contain new Lua API functions listed in https://dev.minetest.net/Changelog#5.9.1_.E2.86.92_5.10.0.

[alerque]

Thanks for the contributions. I split your commit up into one to rename and move things around and another to update the actual contents of the standard, but the end result should be the same as you submitted.

[appgurueu]

I split your commit up into one to rename and move things around and another to update the actual contents of the standard, but the end result should be the same as you submitted.

That makes sense. I've looked at the two commits and confirmed via git diff that the end result is indeed the same. Thanks for splitting it up.

[BuckarooBanzay]

nice, looks good 👍