chore: add .editorconfig

[pythoninthegrass]

EditorConfig is pretty straightforward. Add the extension to whatever your IDE/editor is, drop the config into the root of the repo, and henceforth don't clobber other people's work with crazy formatting modifications (e.g., stripped whitespace on 1000+ lines).

The only not-so-obvious line is root = true; from the docs:

When opening a file, EditorConfig plugins look for a file named .editorconfig in the directory of the opened file and in every parent directory. A search for .editorconfig files will stop if the root filepath is reached or an EditorConfig file with root=true is found.

Happy to remove whatever you think isn't necessary, but honestly if it's not used, it's kinda like forwarding a udp port when only tcp is listening 😼

Closes #29