Update gitignore and format files

[aaronfranke]

I updated the gitignore to be based on other Godot gitignores. It's useful to keep this in sync even if not everything is directly relevant. For example, opening the project in a C#-enabled version of Godot will generate the .mono/ folder even if the project doesn't use C# anywhere.

Also, I ran a formatting script, there were a few scripts that didn't end in newlines, now they do.

[henriiquecampos]

Thanks a lot, @aaronfranke! much appreciated :D