Switch to ruby-lsp VSCode plugin

[ajdubovoy]

resolve https://github.com/lewagon/teachers/issues/1780

It seemed to work for me locally. The only thing I wasn't sure of is if we needed to do anything to make it play nice with rubocop but maybe no...?

[ajdubovoy]

I'm actually just not sure. I'm not a VSCode user and mine has never been able to run rubocop correctly and I've never figured out why 🙈

[ajdubovoy]

But currently we're not installing anything separately for rubocop and I think the default behavior of ruby-lsp is to respect the config actually...I think

[ajdubovoy]

Should we maybe try to merge this for Q4 batches?

[Eschults]

🚀