Document configuration options for user profile mini-app

docs/developers/envvars.rst

@@ -10,6 +10,13 @@ build tasks.
    the notebook app's iframe).
    ``https://hypothes.is/notebook`` by default.
 
+.. envvar:: PROFILE_APP_URL
+
+   The default value for the :option:`profileAppUrl` config setting (the URL of
+   the user profile iframe), used when the host page does not contain a
+   :option:`profileAppUrl` setting.
+   ``https://hypothes.is/user-profile`` by default.
+
 .. envvar:: SIDEBAR_APP_URL
 
    The default value for the :option:`sidebarAppUrl` config setting (the URL of

docs/publishers/config.rst

@@ -475,3 +475,7 @@ These settings configure where the client's assets are loaded from.
 .. option:: notebookAppUrl
 
    ``String``. The URL for the notebook application (Default: ``"https://hypothes.is/notebook"``).
+
+.. option:: profileAppUrl
+
+   ``String``. The URL for the user profile application (Default: ``"https://hypothes.is/user-profile"``).