The CLA bot can now be rerun with a comment. Fix broken CLA links. (#86825)

Author: jeffhandley

CONTRIBUTING.md

@@ -145,11 +145,9 @@ Also do your best to factor commits appropriately, not too large with unrelated
 
 ### Contributor License Agreement
 
-You must sign a [.NET Foundation Contribution License Agreement (CLA)](https://cla.dotnetfoundation.org) before your PR will be merged. This is a one-time requirement for projects in the .NET Foundation. You can read more about [Contribution License Agreements (CLA)](http://en.wikipedia.org/wiki/Contributor_License_Agreement) on Wikipedia.
+You must sign a [.NET Foundation Contribution License Agreement (CLA)](https://cla.dotnetfoundation.org) before your PR will be merged. This is a one-time requirement for projects in the .NET Foundation. You can read more about [Contribution License Agreements (CLA)](http://en.wikipedia.org/wiki/Contributor_License_Agreement) on Wikipedia and the [Microsoft Open Source](https://opensource.microsoft.com/cla/) program.
 
-The agreement: [net-foundation-contribution-license-agreement.pdf](https://github.com/dotnet/home/blob/master/guidance/net-foundation-contribution-license-agreement.pdf)
-
-You don't have to do this up-front. You can simply clone, fork, and submit your pull-request as usual. When your pull-request is created, it is classified by a CLA bot. If the change is trivial (for example, you just fixed a typo), then the PR is labelled with `cla-not-required`. Otherwise it's classified as `cla-required`. Once you signed a CLA, the current and all future pull-requests will be labelled as `cla-signed`.
+You don't have to do this up-front. You can simply clone, fork, and submit your pull-request as usual. When your pull-request is created, it is classified by a CLA bot. If the change is trivial (for example, you just fixed a typo), then the PR is labelled with `cla-not-required`. Otherwise it's classified as `cla-required` and the CLA bot will present the agreement to you on the pull-request. The CLA bot will provide a prompt to sign the CLA through a comment on the pull-request. Once you sign a CLA, the current and all future pull-requests will be labelled as `cla-signed`.
 
 ### File Headers
 

docs/workflow/ci/failure-analysis.md

@@ -43,7 +43,7 @@ Validation may fail for several reasons, and for each one we have a different re
   * Or, amend your commit with `--amend --no-edit` and force push to your branch.
 
 ### Additional information:
-  * In the rare case the license/cla check fails to register a response, close and reopen the PR or push an empty commit.
+  * If the license/cla check fails to register a response, the check can be rerun by submitting a `@dotnet-policy-service rerun` comment to the PR.
   * Reach out to the infrastructure team for assistance on [Teams channel](https://teams.microsoft.com/l/channel/19%3ab27b36ecd10a46398da76b02f0411de7%40thread.skype/Infrastructure?groupId=014ca51d-be57-47fa-9628-a15efcc3c376&tenantId=72f988bf-86f1-41af-91ab-2d7cd011db47) (for corpnet users) or on [Gitter](https://gitter.im/dotnet/community) in other cases.
 
 ## What to do if you determine the failure is unrelated