Add a Spell Checker to the script editor and node editor

[DarinDev1000]

I would love this feature!
It would really help to not misspell my variables.

Also, If anyone could link a plugin that does spell checking, that would be great.

[Calinou]

Spellchecking requires Godot to be able to query spelling dictionaries on the system, as well as querying the languages used for spellchecking (which can be configured system-wide). This is quite complex to implement, especially since it requires OS-specific code.