The content of holocron example post is improved

This commit changes the text of holocron.mdown file, adding info about holocron
features and its basic usage.

Fixed #16
Merge pull request #20 from ikalnitsky/example-improvements

The content of holocron example post is improved
Use Dooku from PyPI

The first public beta version of Dooku was released today (Aug 30, 2014).
Since now we should use only public versions (no dev versions anymore).
Theme style improvements

The commit involves changes:

* color palete - now it's cold, not hot (based on blue)
* styles for tables and blockquotes
* logo contrast was changed