Add weekly 'createTiles' step

.forgejo/workflows/update_weekly.yml

@@ -0,0 +1,18 @@
+on:
+  workflow_dispatch:
+  schedule:
+    - cron: "0 2 * * 0"
+
+jobs:
+  create_archive_tiles:
+    runs-on: [ osm-cache ]
+    steps:
+      - uses: https://source.mapcomplete.org/actions/checkout@v4
+
+      - name: Print data
+        shell: bash
+        run: ls -h /data/planet-latest.pmtiles
+
+      - name: Create new tiles
+        shell: bash
+        run: /data/generateTiles.sh # generated by the script in the MapComplete repo