bash script version watchdog (#462)

* impl version watchdog

* Update update.sh

Co-authored-by: Florian Kinder <florian.kinder@fankserver.com>

* increase update check frequency to per hour

* Update .github/workflows/update.yml

Co-authored-by: Sandro <sandro.jaeckel@gmail.com>

* Update update.sh

Co-authored-by: Sandro <sandro.jaeckel@gmail.com>

* Update update.sh

Co-authored-by: Sandro <sandro.jaeckel@gmail.com>

* Update .github/workflows/update.yml

Co-authored-by: Sandro <sandro.jaeckel@gmail.com>

* prevent schedule running on fork

---------

Co-authored-by: Florian Kinder <florian.kinder@fankserver.com>
Co-authored-by: Sandro <sandro.jaeckel@gmail.com>

.github/workflows/docker.yml

@@ -2,6 +2,9 @@ name: Docker build
 
 on:
   pull_request:
+  push:
+    tags:
+      - latest
 
 jobs:
   build:

.github/workflows/update.yml

@@ -0,0 +1,24 @@
+name: Check Update
+
+on:
+  schedule:
+    - cron: "0 * * * *"
+  workflow_dispatch:
+    inputs:
+      desc:
+        description: "desc"
+        required: false
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    if: github.event_name != 'schedule' || (github.event_name == 'schedule' && github.repository == 'factoriotools/factorio-docker')
+
+    steps:
+      - uses: actions/checkout@v3
+        with:
+          token: ${{ secrets.REPO_TOKEN }}
+
+      - name: Run update script
+        run: ./update.sh
+        shell: bash