Add instructions to check locally whether autoupdate strategy is working

src/utils/resources.py

@@ -420,6 +420,28 @@ class SourcesResource(AppResource):
 
     And the autoupdater will use the matched group (here: `4.1`) as the version.
 
+    You can make sure that your autoupdate strategy is working well immediately (without waiting for the next check on the infra) by doing the following:
+    1. Clone this repo: https://github.com/YunoHost/apps_tools
+    2. In `apps_tools` open a terminal to run the following commands: 
+        ```sh
+        # Create test branch
+        git checkout -b localtest
+
+        # Create a Python virtual environment
+        python -m venv venv
+        source venv/bin/activate
+
+        # Install dependencies (if you don't have pip already installed on your system, check https://pip.pypa.io/en/stable/installation)
+        pip install -r requirements.txt
+      
+        # Run autoupdate script - replace '/path/to/myapp_ynh' with your actual local app path
+        ./autoupdate_app_sources/autoupdate_app_sources.py '/path/to/myapp_ynh'
+        ```
+    3. If the return output includes:
+    - `Apps udpated`, it ran successfully. Note that it will automatically make local changes in your app's `manifest.toml` (which can be discarded as they will be made automatically later online by the YNH infra);
+    - `Apps failed`, the autoupdate stragegy is not working properly - check the debug info;
+    - none of the above but `apps -> Autoupdater just ran, here are the results:`, it ran successfully but the app was already up to date.
+
     ### Provision/Update
     - For elements with `prefetch = true`, will download the asset (for the appropriate architecture) and store them in `/var/cache/yunohost/download/$app/$source_id`, to be later picked up by `ynh_setup_source`. (NB: this only happens during install and upgrade, not restore)