Setup automatic release workflow

.github/workflows/release-on-milestone-closed.yml

@@ -0,0 +1,45 @@
+name: "Automatic Releases"
+
+on:
+  milestone:
+    types:
+      - "closed"
+
+jobs:
+  release:
+    name: "GIT tag, release & create merge-up PR"
+    runs-on: "ubuntu-20.04"
+
+    steps:
+      - name: "Checkout"
+        uses: "actions/checkout@v2"
+
+      - name: "Release"
+        uses: "laminas/automatic-releases@1.0.1"
+        with:
+          command-name: "laminas:automatic-releases:release"
+        env:
+          "GITHUB_TOKEN": ${{ secrets.GITHUB_TOKEN }}
+          "SIGNING_SECRET_KEY": ${{ secrets.SIGNING_SECRET_KEY }}
+          "GIT_AUTHOR_NAME": ${{ secrets.GIT_AUTHOR_NAME }}
+          "GIT_AUTHOR_EMAIL": ${{ secrets.GIT_AUTHOR_EMAIL }}
+
+      - name: "Create Merge-Up Pull Request"
+        uses: "laminas/automatic-releases@1.0.1"
+        with:
+          command-name: "laminas:automatic-releases:create-merge-up-pull-request"
+        env:
+          "GITHUB_TOKEN": ${{ secrets.GITHUB_TOKEN }}
+          "SIGNING_SECRET_KEY": ${{ secrets.SIGNING_SECRET_KEY }}
+          "GIT_AUTHOR_NAME": ${{ secrets.GIT_AUTHOR_NAME }}
+          "GIT_AUTHOR_EMAIL": ${{ secrets.GIT_AUTHOR_EMAIL }}
+
+      - name: "Create and/or Switch to new Release Branch"
+        uses: "laminas/automatic-releases@v1"
+        with:
+          command-name: "laminas:automatic-releases:switch-default-branch-to-next-minor"
+        env:
+          "GITHUB_TOKEN": ${{ secrets.ORGANIZATION_ADMIN_TOKEN }}
+          "SIGNING_SECRET_KEY": ${{ secrets.SIGNING_SECRET_KEY }}
+          "GIT_AUTHOR_NAME": ${{ secrets.GIT_AUTHOR_NAME }}
+          "GIT_AUTHOR_EMAIL": ${{ secrets.GIT_AUTHOR_EMAIL }}