Mention we prefer methods instead of constructors

[fire]

Your Godot version: 2e24b76535dceb9cf18ab8ece3304ed92948c1b5

Issue description: Mention we prefer methods instead of constructors. A pr was trying to add more constructors to a base type. I don't remember the pr @reduz 's comment was in.

https://github.com/godotengine/godot/pull/62814#issuecomment-1207960763

URL to the documentation page (if already existing):

[Calinou]

I don't remember the pr @reduz 's comment was in.

I think you're referring to https://github.com/godotengine/godot/pull/57477#issuecomment-1216641565 :slightly_smiling_face:

Should this be mentioned in Core types?