Clarify license prerequisites for cross-cluster replication tutorial

[leemthompo]

closes #4001, handled as part of triage duty

only changed one line, diff is bigger because I updated list to use standard markdown syntax

OLD

* A license on both clusters that includes {{ccr}}. [Activate a free 30-day trial](../../license/manage-your-license-in-self-managed-cluster.md).

NEW:

- Both clusters must have the same [license](/deploy-manage/license.md) type, and that license must support {{ccr}}.
  - [Activate a free 30-day trial](../../license/manage-your-license-in-self-managed-cluster.md).

[github-actions]

🔍 Preview links for changed docs

• deploy-manage/tools/cross-cluster-replication/ccr-getting-started-prerequisites.md

[kilfoyle]

LGTM! ⛵

[bytebilly]

LGTM 👍