make the languageId of didOpen notifications configurable

[ayame113]

According to the spec, the recommended markdown languageId for textDocument/didOpen requests is "markdown". Currently, the markdown languageId is "github markdown", can you change it?

(The specifications say "If a document refers to one of the programming languages listed below it is recommended that clients use those ids.".)

[UziTech]

the languageId is set by the grammar name. If you want the languageid to be markdown you can use language-markdown instead of language-gfm

[UziTech]

I feel like we should leave this between the grammars and the servers. GFM should be processed differently than CommonMark (markdown). I think the servers might want to know which one they are receiving.

[ayame113]

I think the servers might want to know which one they are receiving.

It makes sense. How about allowing users of this package to configure languageId through the AutoLanguageClient?

example:

class FooBarLanguageClient extends AutoLanguageClient {
  getLanguageIdFromGrammarScope(scopeName: string): string|undefined {
    // If return undefined, the default value will be used
    if (scopeName==='source.gfm') {
      return 'markdown'
    }
  }
}

[UziTech]

I think some sort of override would be ok. @ayame113 wanna create a PR?

[ayame113]

wanna create a PR?

OK, I will do it.