Ensure that class_name / extends respect the official style guide

[TranquilMarmot]

I try and follow the GDScript style-guide as defined in the docs:
https://docs.godotengine.org/en/stable/tutorials/scripting/gdscript/gdscript_styleguide.html

This formatter currently transforms:

class_name StateMachine
extends Node

Into:

class_name StateMachine extends Node

I hate to ask to add more config because it's nice to have an "opinionated" code formatter, but could this be a config value? Or should this formatter align with the official style-guide more closely?

[NathanLovato]

We should generally aim to follow the official style guide. I missed that they were supposed to go on two lines (despite writing the sample script and a bunch of the gdscript style guide rules back in the day!). If you find anything that we missed, don't hesitate to point it out. Anything that's specified in the styleguide basically we want to cover, eventually.