Compress images (#2532)

* Create calibreapp-image-actions.yml

* Update calibreapp-image-actions.yml

* Update calibreapp-image-actions.yml

* Update calibreapp-image-actions.yml

* Update calibreapp-image-actions.yml

* Update calibreapp-image-actions.yml

* Compressed Images

* Update calibreapp-image-actions.yml

* correction on comment

Co-authored-by: efb4f5ff-1298-471a-8973-3d47447115dc <efb4f5ff-1298-471a-8973-3d47447115dc@users.noreply.github.com>

.github/workflows/calibreapp-image-actions.yml

@@ -0,0 +1,28 @@
+# Compress images on demand (workflow_dispatch), and at 12am every Sunday (schedule).
+# Open a Pull Request if any images can be compressed.
+name: Compress Images
+on:
+  workflow_dispatch:
+  schedule:
+    - cron: '0 0 * * 0'
+jobs:
+  build:
+    name: calibreapp/image-actions
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout Repo
+        uses: actions/checkout@v2
+      - name: Compress Images
+        id: calibre
+        uses: calibreapp/image-actions@main
+        with:
+          githubToken: ${{ secrets.GITHUB_TOKEN }}
+          compressOnly: true
+      - name: Create New Pull Request If Needed
+        if: steps.calibre.outputs.markdown != ''
+        uses: peter-evans/create-pull-request@v3
+        with:
+          title: Compressed Images Nightly
+          branch-suffix: timestamp
+          commit-message: Compressed Images
+          body: ${{ steps.calibre.outputs.markdown }}