add a nice footer

[empeje]

well, we don't have a footer and after reading all the page it is not nice to see, better to have some footer.

[xyb994]

How much connection with OLE do we want to show? It's time to reserve treehouses.io social media accounts?

[empeje]

Well, I don't know this direction @xyb994, @dogi should know better about this. However, IMO @dogi wants treehouses as a separate project that independent of OLE. Just enough information about OLE is required in treehouses social media/web.