* Adding file writer for Markdown tables. No testing yet.
* Unit tests for the markdown writer
* Wiring up the factory and and request types
* Wiring up changes for Markdown serialization in serialization service
* Couple last minute tweaks
* Changes as per PR comments
* Revert temp testing code. 🙈
* Fluent assertions in SerializationServiceTests.cs
Co-authored-by: Ben Russell <russellben@microsoft.com>