fix: gha skip whitespace trim on body (#73)

this also added a github workflow example

examples/on-pr-merge/automated-workflow.yaml

@@ -0,0 +1,53 @@
+name: Automated Backporting on PR merge using Git Backporting
+
+on:
+  pull_request_target:
+    types: [closed, labeled]
+    branches:
+      - main
+
+env:
+  GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+jobs:
+  compute-targets:
+    if: ${{ github.event.pull_request.state == 'closed' && github.event.pull_request.merged }}
+    runs-on: ubuntu-latest
+    outputs:
+      target-branches: ${{ steps.set-targets.outputs.targets }}
+    env:
+      LABELS: ${{ toJSON(github.event.pull_request.labels) }}
+    steps:
+      - name: Set target branches
+        id: set-targets
+        uses: kiegroup/kie-ci/.ci/actions/parse-labels@main
+        with:
+          labels: ${LABELS}
+  
+  backporting:
+    if: ${{ github.event.pull_request.state == 'closed' && github.event.pull_request.merged && needs.compute-targets.outputs.target-branches != '[]' }}
+    name: "[${{ matrix.target-branch }}] - Backporting"
+    runs-on: ubuntu-latest
+    needs: compute-targets
+    strategy:
+      matrix: 
+        target-branch: ${{ fromJSON(needs.compute-targets.outputs.target-branches) }}
+      fail-fast: true
+    steps:    
+      - name: Checkout
+        uses: actions/checkout@v3
+        with:
+          fetch-depth: 0
+      - name: Backporting
+        uses: ./
+        with:
+          dry-run: true
+          pull-request: ${{  github.event.pull_request.html_url }}
+          target-branch: ${{ matrix.target-branch }}
+          auth: "${{ env.GITHUB_TOKEN }}"
+          title: "[${{ matrix.target-branch }}] ${{ github.event.pull_request.title }}"
+          body-prefix: "**Backport:** ${{  github.event.pull_request.html_url }}\r\n\r\n**Note**: comment 'ok to test' to properly launch Jenkins jobs\r\n\r\n"
+          body: "${{ github.event.pull_request.body }}"
+          labels: "cherry-pick :cherries:"
+          inherit-labels: false
+          bp-branch-name: "${{ matrix.target-branch }}_${{ github.event.pull_request.head.ref }}"