message: add tags back in the adp readme
diff: @@ -31,6 +31,8 @@ openapi-subtype: rpaas
  tag: package-2021-02-01-preview
  ```
  +### Tag: package-2020-07-01-preview
  +
  ```yaml $(tag) == 'package-2020-07-01-preview'
  version: 2020-07-01-preview
  version-with-underscores: 2020_07_01_preview
  @@ -38,6 +40,8 @@ input-file:
  - Microsoft.AutonomousDevelopmentPlatform/preview/2020-07-01-preview/adp.json
  ```
  +### Tag: package-2021-02-01-preview
  +
  ```yaml $(tag) == 'package-2021-02-01-preview'
  version: 2021-02-01-preview
  version-with-underscores: 2021_02_01_preview
  