Update SIGN-IN.md

[ItAnthon]

Looked empty so i added the 2 account types

[GaucovyAero]

add more info about the login types ples, that like the microsoft account only lets you log in when you have bought mc: java edition, and that the local account works only if you are already logged into a microsoft account, etc.

[ItAnthon]

The whole local account thing as of writing only works on the iOS version (unless it’s planned for android)?

but ill go ahead and add these details in shortly

[ItAnthon]

Added the details, let me know!