Language Server & `vscode-graphql` Maintainers & Contributors Needed!

Hello friends!

I could use some help with this in particular, and would be willing to schedule recorded sessions to help onboard people to this ecosystem

## tasks

in order of priority

1. clear out known bugs in `graphql-language-service-server`
a. error handling & logging
b. broken support for schema SDL files (potentially related to file URI issues introduced with a PR to convert uris to node file:/// urls in the past year?)
c. broken support for definitions lookup (which may be related to the above)
d. remote schema cacheing may be setup to cache multiple schemas instead of 1? are definitions working there?
e. overall, improve remote schema cacheing and test coverage to ensure it's actually working
2. report graphql-config presence with a proper notification from the server, so that it's client agnostic (i.e. works with clients that aren't vscode)
3. replace all internal usage of `findGraphQLTags` and `getDocument` and with `CodeFileLoader` loaded files from `graphql-config` or individually loaded with the loaders themselves (talk to @dotansimha and the guild about this!)
4. help migrate `vscode-graphql` into the `graphiql` monorepo
5. finish up syntax support for `grammars` in `vscode-graphql`, add syntax support for more languages (vue, svelte, python, swift, php, java, rust, elixir, etc)

## why `vscode-graphql`?

We use it as our reference implementation, and plan on merging it into the repo

## Local dev setup:

0. setup `vscode-graphql`
1. setup `graphiql` monorepo and yarn link to `vscode-graphql`
2. run Extension debugger from vscode in `vscode-graphql`

Then, open some example projects with various configs and experiment.
Use the output channel for debugging.