* Revert "Update requirement for Query type in mutation docs (#1213)"
This reverts commit a9625dac0e.
* Add test to check that Query type must be defined
* Revise documentation
- Add missing reference to `flask-graphql` in integrations
- align documentation for resolver arguments (use root for 1st argument
instead of self)
- explore use of `parent` instead of `root` for first argument
- clarify resolvers and object type documentation
- add documentation for Meta class options for ObjectType
- expand quickstart documentation for first time users
- streamline order of documentation for first time users (broad ->
specific)
- document resolver quirks
* explict imports from graphene
* rename doc refs for resolvers
* suggestions typos and graphene import
