Make how to contribute/edit site more obvious

[danfowler]

No description provided.

[rufuspollock]

++1. I think we could do some quick guerilla user testing to see if people even see the "improve" this page on the side - my guess is no. I think we need to make this more prominent and we could experiment with various options:

• Colour it (and get a better icon when we lose the text on small pages)
• Move out from RHS of page (people ignore) to top of main section of text
  • may not need to move, could just duplicate