docs: Importing initial set of library documentation from wiki

To build documentation, doxygen (+graphviz dot) and sphinx-build are
required.  Manpages are build and installed during `./waf build` stage
if sphinx-build is present.

Documentation can be build using the following commands:

    # Full set of documentation (tutorials + API) in build/docs
    ./waf docs

    # Only tutorials in `build/docs`
    ./waf sphinx

    # Only API docs in `build/docs/doxygen`
    ./waf doxgyen

Change-Id: I4c08be08ca3e22068db54584f99467aa6cf38d04
Refs: #1462
diff --git a/docs/manpages.rst b/docs/manpages.rst
new file mode 100644
index 0000000..8300f89
--- /dev/null
+++ b/docs/manpages.rst
@@ -0,0 +1,6 @@
+Manpages
+========
+
+.. toctree::
+   manpages/ndnsec
+   :maxdepth: 1