message: Add $(multiapi) to QnA Maker's readme.md
  Generators were processing every tag when only a single one was desired. This is the common solution to support multi-api SDKs.
diff: @@ -74,7 +74,7 @@ These settings apply only when `--tag=release_5_0_preview.2` is specified on the
  input-file: preview/v5.0-preview.2/QnAMaker.json
  ```
  -``` yaml
  +``` yaml $(multiapi)
  batch:
  - tag: release_4_0
  - tag: runtime_release_4_0
  