Add Makefile for compiling and serving

`make` will compile the blog posts, and `make chapo` will start
the python SimpleHTTPServer on port 8000.
pelican.conf.py: Add site url

Also, use relative URLs when developing.
pelican.conf.py: Clean up blogroll and social links

Remove pre-defined example links and make the formatting a bit eas-
ier to follow.
Makefile: Can you taste it now?
Merge branch 'makefile' of https://github.com/alanorth/nairobilug.or.ke

* 'makefile' of https://github.com/alanorth/nairobilug.or.ke:
  Makefile: Can you taste it now?
  Add Makefile for compiling and serving