Add package_linter to github actions

.github/workflows/package_linter.yml

@@ -0,0 +1,41 @@
+name: YunoHost apps package linter
+
+on:
+  # Allow to manually trigger the workflow
+  workflow_dispatch:
+  push:
+    branches:
+      - master
+      - testing
+  pull_request:
+  schedule:
+    - cron: '0 8 * * *'
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+
+      - name: Set up Python
+        uses: actions/setup-python@v4
+        with:
+          python-version: '3.9'
+
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade pip
+          pip install toml
+
+      - name: 'Clone YunoHost apps package linter'
+        run: |
+          git clone --depth=1 https://github.com/YunoHost/package_linter ~/package_linter
+
+      - name: 'Run linter'
+        run: |
+          ~/package_linter/package_linter.py . > linter_logs && cat linter_logs
+
+      - name: 'Analyze linter logs'
+        run: |
+          grep "Not even a warning\!" linter_logs
+