Add charity links to public bodies

If the body is a charity, provide a link to its registration info
Add charity links to public bodies

If the body is a charity, provide a link to its registration info
Merge branch '875-remove-charities' of ssh://git.mysociety.org/data/git/public/whatdotheyknow-theme into 875-remove-charities
Merge branch '875-remove-charities'