Can --reorder-code can be put as a flag in the .editorconfig ?

I'd like to be able to run gdscript-formatter without having it to pass options everytime I use the tool. This allow to only write settings once (e.g. in `.editorconfig`) without worrying about the option we use and to avoid duplication.

This could be nice to have if possible :
```.editorconfig
root = true

[*]
charset = utf-8

[*.gd]
max_line_length = 120
gdscript_formatter_reorder_code = true

[addons/**/*.gd]
gdscript_formatter_exclude = true
```

Start by examining the formatter's configuration handling and how the --reorder-code option is parsed. Then inspect any existing .editorconfig support and related tests. Done means the option can be set with gdscript_formatter_reorder_code in .editorconfig and works without passing the command-line flag.

索引モデルが issue の本文から書いたものです。