message: Associate .gql with graphql language in GraphQLProject
  Codegen wasn't working for me with my files ending in ".gql". As my IDE plugin recognizes "*.gql" files as graphql, this is very confusing.
  I see two possible further improvements:
  1. Warn when including a file without language association
  2. Fallback to `graphql` language
diff: @@ -34,6 +34,7 @@ export type DocumentUri = string;
  const fileAssociations: { [extension: string]: string } = {
  ".graphql": "graphql",
  + ".gql": "graphql",
  ".js": "javascript",
  ".ts": "typescript",
  ".jsx": "javascriptreact",
  