CSS Fix for the tables generated via orgitdown

- Previously tables were looking like follows : 
![image](https://cloud.githubusercontent.com/assets/3327363/3184729/3137704e-ec89-11e3-9305-4f9e70d88ea0.png)

- But now table CSS has been fixed and appearance changed as follows : 
![image](https://cloud.githubusercontent.com/assets/3327363/3184743/6dddca20-ec89-11e3-9e88-44d74deb8d62.png)