Added clarifying comments related to GraphQL return types

app/controllers/graphql_controller.rb

@@ -4,6 +4,8 @@ class GraphqlController < ApplicationController
   skip_authorization_check
 
   def query
+    # ConsulSchema.execute returns the query result in the shape of a Hash, which
+    # is sent back to the client rendered in JSON
     render json: ConsulSchema.execute(
       params[:query],
       variables: params[:variables] || {}