Update and simplify website

I've made updates to the website.  Moved the Download page into the Github wiki so it is easily updateable and added the appropriate content to the wiki. Merged the about page with the Documentation page as the documentation page felt a little redundant.  Updated the Documentation, Download and News pages in case someone is linking to them  to note that they were no longer updated and where to go now. Patch notes should be added to the download pages in the wiki, and other news can go into Readme.md.  I hope you like the changes, if not then dont worry it didn't take me long.