Expose config for identifying supported vendors

unfortunately must identify vendors at each app node separately, but
this is definitely still an improvement..

tailbone/views/master.py

@@ -4359,6 +4359,21 @@ class MasterView(View):
 
     def configure_get_context(self, simple_settings=None,
                               input_file_templates=True):
+        """
+        Returns the full context dict, for rendering the configure
+        page template.
+
+        Default context will include the "simple" settings, as well as
+        any "input file template" settings.
+
+        You may need to override this method, to add additional
+        "custom" settings.
+
+        :param simple_settings: Optional list of simple settings, if
+           already initialized.
+
+        :returns: Context dict for the page template.
+        """
         context = {}
         if simple_settings is None:
             simple_settings = self.configure_get_simple_settings()