feat: add strategy rebase

Add strategy `rebase` that rebases the commits in the target branch onto the source branch.

Closes #1

README.md

@@ -27,11 +27,12 @@ jobs:
           #   Optional
           #   Default: `beta`
           target: "v1"
-          # The strategy to use, if fast-forward is not possible (merge, force, fail).
+          # The strategy to use, if fast-forward is not possible (merge, rebase, force, fail).
           #   Optional
           #   Default: `merge`
           #   Possible values:
           #     - `merge`:  merge the source branch into the target branch
+          #     - `rebase`: rebase the target branch onto the source branch
           #     - `force`:  force push the source branch to the target branch (overrides any changes on the target 
           #                 branch)
           #     - `fail`:   pushes the source branch to the target branch, fails if the target branch contains changes 

action.yml

@@ -50,6 +50,14 @@ runs:
       if: inputs.strategy == 'merge'
       run: git push
       shell: bash
+    - name: Rebase ${{ inputs.target }} onto ${{ inputs.source }}
+      if: inputs.strategy == 'rebase'
+      run: git rebase ${{ inputs.source }} ${{ inputs.target }}
+      shell: bash
+    - name: Force push ${{ inputs.target }}
+      if: inputs.strategy == 'rebase'
+      run: git push --force origin ${{ inputs.target }}
+      shell: bash
     - name: Force push ${{ inputs.source }} to ${{ inputs.target }}
       if: inputs.strategy == 'force'
       run: git push --force origin ${{ inputs.source }}:${{ inputs.target }}