message: Update swagger-checklist.md
  Adding Validation rule that ensures x-ms-pageable operations have a 200 response defined
diff: @@ -245,6 +245,8 @@ For example, [NetworkInterface.ipConfigurations](https://github.com/Azure/azure-
  - :white_check_mark: **M2058**: Paths in x-ms-paths must overload a normal path in the paths section, i.e. a path in the x-ms-path must either be same as a path in the paths section or a path in the paths sections followed by additional parameters.
  +- :white_check_mark: **M2060**: x-ms-pageable operations must have a 200 response defined.
  +
  ### SHOULD
  - [ ] **S2000**: If a parameter or a model property indicates that it is some "kind/type" of an artifact that can have a value from set of possible values, then it *SHOULD* have an `"enum": ["Array of possible values"]` constraint on that entity. It *MUST* also use the ["x-ms-enum"](https://github.com/Azure/azure-rest-api-specs/blob/master/documentation/swagger-extensions.md#x-ms-enum) extension. If creating an enum is not possible, then the values need to be documented in description. If the number of allowed values is huge, add a link to some kind of external documentation in the description, where those values are defined.
  