add RPSaaS comments (Azure#21801)

Author: ruowan

.github/comment.yml

@@ -41,6 +41,16 @@
     label: NewApiVersionRequired
     onLabeledComments: "<b>NewApiVersionRequired reason:</b></br> </br><b>A service’s API is a contract with customers and is represented by using the api-version query parameter. Changes such as adding an optional property to a request/response or introducing a new operation is a change to the service’s contract and therefore requires a new api-version value. This is critically important for documentation, client libraries, and customer support. </b> </br></br> EXAMPLE: if a customer calls a service in the public cloud using <b>api-version=2020-07-27</b>, the new property or operation may exist but if they call the service in a government cloud, air-gapped cloud, or Azure Stack Hub cloud using the same api-version, the property or operation may not exist. Because there is no clear relationship between the service api-version and the new property/operation, customers can’t trust the documentation and Azure customer have difficulty helping customers diagnose issues. In addition, each client library version documents the service version it supports. When an optional property or new operation is added to a service and its Swagger, new client libraries must be produced to expose this functionality to customers. Without updating the api-version, it is unclear to customers which version of a client library supports these new features.  "
 
+- rule:
+    type: label
+    label: CI-NewRPNamespaceWithoutRPaaS
+    onLabeledComments: "Hi @${PRAuthor} This PR was flagged for introducing a new RP namespace that is not being onboarded with [RPaaS](https://armwiki.azurewebsites.net/rpaas/overview.html). Merging this PR to the main branch will be blocked as RPaaS is required for new RPs. To resolve this and allow the PR to be merged into the main branch, please [use RPaaS to onboard the new RP](https://armwiki.azurewebsites.net/rpaas/gettingstarted.html)."
+
+- rule:
+    type: label
+    label: CI-RpaaSRPNotInPrivateRepo
+    onLabeledComments: "Hi @${PRAuthor} This PR was flagged for attempting to introduce a new RP namespace to the main branch without first merging the new RP to the RPSaaSMaster branch. Please add the new RP in a merge to RPSaaSMaster before continuing the merge to main."
+
 - rule:
     type: label
     label: CI-FixRequiredOnFailure