Doc: running external tools from the locator

Change-Id: Id2040085692e1e8b8413935bd090428e5138fe68
Reviewed-by: Eike Ziller <eike.ziller@theqtcompany.com>

doc/src/editors/creator-editors.qdoc

@@ -2465,6 +2465,8 @@
         \li Executing version control system commands (\c {git}). For more
             information, see \l{Using Version Control Systems}
 
+        \li Running external tools (\c x)
+
     \endlist
 
     To use a specific locator filter, type the assigned prefix followed by

doc/src/howto/creator-external-tools.qdoc

@@ -36,6 +36,9 @@
     for use. You can change their default configurations and configure new
     tools.
 
+    To run the tools, select \uicontrol Tools > \uicontrol External, or use the
+    \c x filter in the locator.
+
     \section1 Using Qt Linguist
 
     You can use the Qt Linguist release manager tools, lupdate and lrelease,