docs: Adding coding style document and other small updates

Change-Id: I5ab036a2225e3ac456c69558352f0c6832dd2d2f
diff --git a/docs/index.rst b/docs/index.rst
index db36d09..58462f4 100644
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -4,6 +4,7 @@
 `API documentation (doxygen) <doxygen/annotated.html>`_
 
 .. toctree::
+   code-style
    examples
    tutorials/security-library
    tutorials/utils-ndn-regex