Browse offline documentation with Tor Browser instead of Yelp

We’re having a few issues (#7285 (closed), #7390 (closed)) on Wheezy for browsing the offline doc with Yelp. We can move back to browsing it with the Tor Browser, as the issue that initially had us move to Yelp has vanished.

Feature Branch: bugfix/7285-browse-doc-with-iceweasel

Related issues

Related to #7285 (closed)
Related to #7390 (closed)

Original created by @intrigeri on 7391 (Redmine)

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information