add social media icons & rename sample.css to style.css

Hi Sarn,

I added icons for Facebook, Twitter, GitHub and YouTube on the footer of all the web pages.
-I had to move the HTML5 validator and other text to the side to fit them in. The validator also points to Oranuch's Hills Account by the way.
-The links on the left column were removed since they became redundant.

Also, I renamed "sample.css" to" style.css" since that seemed more appropriate.

Since I made more changes than I intended, I put the differences on a different branch so you and others can review my work and determine if you want to make changes or merge it with master. If you do, everyone else would need to pull the updates before submitting more pull requests.

Thanks,

Jason