add tool section to urldispatcher (#436)

appdev/guides/importing-CH-urldispatcher.rst

@@ -134,6 +134,17 @@ Let's check if ``Qt.application.arguments`` is not empty and if not, if any argu
 
 Remember to check that %u (to receive 1 URL) or %U (to receive 1 or more URLs) is present under the ``Exec`` line in the `.desktop <https://gitlab.com/ubports-linphone/linphone-simple/-/blob/master/linphone.desktop.in#L7>`_ file of the app.
 
+Tools
+-----
+
+From command line, ``url-dispatcher-dump`` command will give you the full list of registered protocol schemes and their corresponding app.
+
+Another usefull tool, but not installed by default on devices is ``url-dispatcher-tools``, it allows you to simulate a call from a third party app. e.g: ``url-dispatcher https://youtu.be/CIX-a-i6B1w`` will launch youtube webapp.
+
+To install, it make your partition writable (``sudo mount -o rw,remount /``) and install it via ``sudo apt install url-dispatcher-tools``
+
+
+
 What happens if more than one app has the same URL type defined?
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