Help: Organize top-level index

Divide the list of manuals into separate sections each with its own
title.

Help/index.rst

@@ -1,30 +1,48 @@
-CMake Reference Documentation
-#############################
+Command-Line Tools
+##################
 
-.. only:: html
+.. toctree::
+   :maxdepth: 1
+
+   /manual/cmake.1
+   /manual/ctest.1
+   /manual/cpack.1
 
- Reference Manuals:
+Interactive Dialogs
+###################
 
 .. toctree::
    :maxdepth: 1
 
-   /manual/ccmake.1
-   /manual/cmake.1
    /manual/cmake-gui.1
-   /manual/cpack.1
-   /manual/ctest.1
+   /manual/ccmake.1
+
+Reference Manuals
+#################
+
+.. toctree::
+   :maxdepth: 1
+
    /manual/cmake-commands.7
    /manual/cmake-generators.7
    /manual/cmake-modules.7
    /manual/cmake-policies.7
    /manual/cmake-properties.7
    /manual/cmake-variables.7
-   /manual/cmake-generator-expressions.7
+
+Other Manuals
+#############
+
+.. toctree::
+   :maxdepth: 1
+
    /manual/cmake-developer.7
+   /manual/cmake-generator-expressions.7
 
 .. only:: html
 
- Index and Search:
+ Index and Search
+ ################
 
  * :ref:`genindex`
  * :ref:`search`