Read yaml configurations in autorest.md/readme.md

Autorest codegen present configurations in autorest.md/readme.*.md as yaml format. The mock-service-host may need to use these configurations to mock response better, one real instance of that is the "request-path-to-parent" in .net SDK.

This issue is not aimed to support all autorest directives or all .net sdk configurations in mock-service-host. Just for parsing autorest.md make them readable to mock-service-host.