Syntax highlight GraphQL template strings

[jaydenseric]

language-babel for Atom does this really well, supporting:

// Apollo
gql``

// Relay
Relay.QL``
graphql``

// No template tag function
/* GraphQL */``

Currently no VS Code extension supports the comment syntax for plain strings, which is annoying as a plain template string is the basic way to define types for makeExecutableSchema from graphql-tools.

Adding this feature would make this package a one-stop-shop; at the moment I have kumarharsh/graphql-for-vscode installed just to highlight the template strings.