Update documentation to add rebase logic

Author: Tecoddy

content/en/dora_metrics/setup/deployments.md

@@ -301,6 +301,8 @@ If the two metadata entries are defined for a service, only `extensions[datadogh
 - When using "Squash" to merge pull requests:
   - For GitHub and GitLab: Metrics are emitted for the original commits.
   - For other Git providers: Metrics are emitted for the new commit added to the target branch.
+- When using "Rebase", either manually or to merge pull requests:
+  - For all Git providers: Metrics are emitted based on the original commit timestamps, while the displayed SHA corresponds to the newly created rebased commit.
 
 ## Calculating change failure rate