Support SyntaxTree options from .streerc file

[molawson]

👋🏼 First off, this project is really exciting, especially it's SyntaxTree integration!

Starting with v3.3.0, SyntaxTree has supported storing CLI options in an .streerc file. Right now, running the format command with this LSP only uses the SyntaxTree defaults.

Are there any plans to support that .streerc file?

If there's an appetite for this from the maintainers' end, I'd be happy to take a swing at a PR.

[vinistock]

Thank you for the interest in the project!

I think it makes perfect sense to read configurations from the .streerc file, feel free to take a stab at the PR.

Keep in mind that we most certainly only want to read and parse configurations once, similar to what we do in RuboCop.