message: removed mistake in readme file
diff: @@ -124,6 +124,6 @@ If there are files that should not be in the `all-api-versions` set,
  uncomment the `exclude-file` section below and add the file paths.
  ``` yaml $(tag) == 'all-api-versions'
  -exclude-file:
  -- $(this-folder)/Microsoft.Peering/preview/2019-08-01-preview/peering.json
  +# exclude-file:
  +#- $(this-folder)/Microsoft.Peering/preview/2019-06-01-preview/peering.json
  ```
  