[Docs] Improve documentation of eslint config

[SimonSimCity]

Background:

When looking at the current documentation (https://zed.dev/docs/languages/javascript#eslint) I was wondering whether I could add some custom rules, that are reported in addition to the rules defined in my eslint file. So far so good - but I had a very hard time finding where those configurations are defined.

What I want:

A better documentation of where the configuration you provided in the documentation https://zed.dev/docs/languages/javascript#eslint can be looked up at. If I'm correct, this zed by default uses https://github.com/microsoft/vscode-eslint, where the types of the configuration
can be found here: https://github.com/microsoft/vscode-eslint/blob/main/%24shared/settings.ts#L156.

Just links like these would be extremely helpful to see where examples come from and where I can look things up which I want to extend.

[lukejans]

Yeah, I agree with this! I think it's because most settings should be configured through an ESLint config file, but it would be nice for the Zed docs to have an ESLint and Prettier section. Or, for that matter, a section for any tool or language server that is built into the Zed editor.