Doc: Describe filtering in output panes

Task-number: QTCREATORBUG-16356
Change-Id: I995ddbe8ae06c38935f699ed0f1cb73418b6f401
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

doc/src/howto/creator-ui.qdoc

@@ -336,7 +336,7 @@
 
     \title Viewing Output
 
-    \image qtcreator-task-pane.png
+    \image qtcreator-general-messages.png "General Messages output pane"
 
     The task pane in \QC can display one of the following panes:
 
@@ -374,6 +374,9 @@
     up in the pane. In these panes, you can also use the zoom buttons to increase and
     decrease the text size of the output.
 
+    To filter the output, enter a string in the \uicontrol Filter field.
+    Filtering is not supported in all output panes.
+
     To open the \uicontrol{General Messages} and
     \if defined(qtcreator)
     \l{Using Version Control Systems}{Version Control}
@@ -444,7 +447,7 @@
     \uicontrol {Filter Tree}
     and then select a filter.
 
-    \image qtcreator-build-issues.png
+    \image qtcreator-issues.png "Issues output pane"
 
     Right-clicking on a line brings up a context menu with actions that you can
     apply to the contents of the line. You can remove a line, copy its contents
@@ -510,7 +513,7 @@
     The \uicontrol{Compile Output} is a more detailed version of information
     displayed in the \uicontrol{Issues} pane.
 
-    \image qtcreator-compile-pane.png
+    \image qtcreator-compile-output.png "Compile Output pane"
 
     Double-click on a file name in an error message to open the file in the
     code editor.