Enable low-code CDK users to specify schema in the manifest
Also update documentation:
* Add inline schema loader info to yaml-overview.md
* Include inline schema info in tutorial
* replace emptySchemaLoader with DefaultSchemaLoader
* fix test name
* fix test
* add logging for when we default to the empty schema
* increment patch version
* fix formatting
* update changelog
* use mockschemaloader as the default and rename JsonSchema to JsonFileSchemaLoader
* rename mock to EmptySchemaLoader
* retain existing JsonSchema while hacktoberfest is still in progress
* bump version and changelog
* replace file retrieval with pkgutil to fix getting schema files
* slightly better error handling on missing files
* filter our schema gen warnings for some classes that cannot generate schemas
* add comment for todo
* add changelog and setup before publish