Adding swagger sorting command to tcp-client (#8730)

* Adding swagger sorting command to tcp-client

* PR comment

* Adding test to verify sort-swagger

* added expected file to check against

Author: allenjzhang

tools/tsp-client/README.md

@@ -45,6 +45,9 @@ Generate a client library from a TypeSpec project. The `generate` command should
 ### convert
 Convert an existing swagger specification to a TypeSpec project. This command should only be run once to get started working on a TypeSpec project. TypeSpec projects will need to be optimized manually and fully reviewed after conversion. When using this command a path or url to a swagger README file is required through the `--swagger-readme` flag.
 
+### sort-swagger
+Sort an existing swagger specification to be the same content order with TypeSpec generated swagger. This will allow you to easily compare and identify differences between the existing swagger and TypeSpec generated one. You should run this command on existing swagger files and check them in prior to creating converted TypeSpec PRs.
+
 ## Options
 ```
   --arm                     Convert ARM swagger specification to TypeSpec       [boolean]