[FR] Add an option to use custom typescript services in Atom

[Goodwine]

I have a custom version of the typescript node package and I wish this plugin could load that one instead of the bundled version in packages.json.

For example the .vscode/settings.json file in this repo has "typescript.tsdk": "node_modules/typescript/lib".

I understand this file is not related to the repo at all, but...
If something like this could be done for Atom, so that I can specify my own tsdk, that would be awesome.

Alternatively, if atom-languageclient could load the typescript node package from $NODE_PATH and fallback to the bundled one, that would be cool too.