Change `queries` to `fields_of(type_name)`

This makes it completely explicit what the 'queries' are in this case.

lib/gitlab/graphql/docs/helper.rb

@@ -143,10 +143,9 @@ module Gitlab
           graphql_interface_types.map { |t| t.merge(fields: t[:fields] + t[:connections]) }
         end
 
-        # 'queries' are the fields of the Query type
-        def queries
+        def fields_of(type_name)
           graphql_operation_types
-            .find { |type| type[:name] == 'Query' }
+            .find { |type| type[:name] == type_name }
             .values_at(:fields, :connections)
             .flatten
             .then { |fields| sorted_by_name(fields) }

lib/gitlab/graphql/docs/templates/default.md.haml

@@ -26,8 +26,8 @@
   The `Query` type contains the API's top-level entry points for all executable queries.
 \
 
-- queries.each do |query|
-  = render_full_field(query, heading_level: 3, owner: 'Query')
+- fields_of('Query').each do |field|
+  = render_full_field(field, heading_level: 3, owner: 'Query')
   \
 
 :plain