doc: style: move cmake into style guidelines

Consolidate all style guidelines into one place, moving cmake style
guidelines under the contribute section.

Signed-off-by: Anas Nashif <anas.nashif@intel.com>

doc/build/cmake/index.rst

@@ -44,7 +44,7 @@ source file :file:`src/main.c`, behavior that we surely do not want. The
 paths of a target library.
 
 When introducing build system code using CMake or adding new CMake files,
-please follow the style guidlines outline :ref:`here <cmake-style>`.
+please follow the style guidelines outlined :ref:`here <cmake-style>`.
 
 
 Build and Configuration Phases

doc/contribute/style_guidelines.rst

@@ -4,6 +4,11 @@
 Coding Style Guidelines
 #######################
 
+.. toctree::
+   :maxdepth: 1
+
+   style/cmake.rst
+
 C Code and General Style
 ************************