Doc: Describe CMake changes

- Divide the "Setting Up CMake" into several how-to topics.
- Rename it as "CMake" and link to all the new topics.
- Update related topics accordingly.

Task-number: QTCREATORBUG-29361
Task-number: QTCREATORBUG-29392
Change-Id: Ib8f4a1951b5ffd7eaa25a4e5cf40e7bb252f9cf4
Reviewed-by: Cristian Adam <cristian.adam@qt.io>

doc/qtcreator/src/user-interface/creator-file-system-view.qdoc

@@ -110,5 +110,7 @@
     To stop the synchronization with the file currently open in the
     editor, deselect \inlineimage icons/linkicon.png
     (\uicontrol {Synchronize with Editor}).
+
+    \sa {View CMake project contents}, {Projects}
     \endif
 */

doc/qtcreator/src/user-interface/creator-projects-view.qdoc

@@ -85,7 +85,7 @@
             {generic projects}.
         \li Add existing files and directories.
         \li Add libraries. For more information, see
-            \l{Add libraries to projects}.
+            \l{Add libraries to qmake projects}.
         \li Add and remove subprojects.
         \li Find unused functions.
         \endif
@@ -151,5 +151,7 @@
     from the version control system in brackets after the project name.
     \QC currently implements this for Git (the view displays the branch name
     or a tag) and ClearCase (the view displays the branch name).
+
+    \sa {View CMake project contents}, {File System}
     \endif
 */