Describe what to do after an app is added.

- fixes https://gitlab.com/fdroid/fdroiddata/issues/1323

CONTRIBUTING.md

@@ -90,3 +90,29 @@ to appear in our repository.
 * If you haven't tested your build, say so in the merge request.
 
 * Check for CI errors once you have opened your Merge Request
+
+
+### After You Added Your App
+
+- Once your app metadata is merged, it can take a day or more for the
+    build system to build the app.
+- If you have enabled auto-updates, F-Droid will build new versions from tags
+    automatically.
+
+    ```
+    Auto Update Mode:Version v%v
+    Update Check Mode:Tags
+    ```
+- You may like to add [localization and screenshots], so users can have a glance
+    at the app in pictures and in their preferred language.
+- You can advertise the download of your app in this app store using the
+    [official grafic][get-it-on-fdroid].  
+    <img src="https://f-droid.org/badge/get-it-on.png" height="75">
+
+    ```
+    <img src="https://f-droid.org/badge/get-it-on.png" height="75">
+    ```
+
+
+[localization and screenshots]: https://fdroid.gitlab.io/fdroid-website/docs/All_About_Descriptions_Graphics_and_Screenshots/
+[get-it-on-fdroid]: https://f-droid.org/badge/get-it-on.png