Doc: Add a workaround for changing the default editor

You can move a filename pattern from one MIME type to
another to open the file in another editor by default.
This might be useful when working on file types that are
not registered MIME types and that clash with the
registered ones.

Change-Id: Ic68f7db7bd58fab48a2aa6edbffc123f13c63899
Reviewed-by: André Hartmann <aha_1980@gmx.de>

doc/src/editors/creator-only/creator-mime-types.qdoc

@@ -105,6 +105,16 @@
 
     \endlist
 
+    Even if an alternative editor is not listed for a MIME type, you can still
+    change the editor that is used to open the files of a particular type.
+    Remove the filename extension from the current MIME type and add it to a
+    MIME type that is handled by the editor you want to use. For example, to
+    edit Linux kernel device tree source (.dts) files with the text editor,
+    delete the pattern \c {*.dts} from the MIME type \c {audio/vnd.dts} (where
+    it represents the digital surround audio file format), and add it to the
+    \c {text/plain} MIME type. You can use the \uicontrol Filter field to find
+    the MIME type that currently contains a filename extension.
+
     To revert the changes you have made to the MIME type definitions,
     select \uicontrol {Reset MIME Types}. To revert the changes you have
     made to the default editors, select \uicontrol {Reset Handlers}.