Add Privacy Badger help

[lorennorman]

Privacy Badger is an awesome browser plugin from the EFF that many people use to protect their privacy in the face of rapacious corporate intrusion into our beautiful open web. Unfortunately, it foils new users of Paperize by blocking their login and failing silently.

Let's add a help section to the docs to include issues like this with helpful advice to get around the problem.

For Privacy Badger, the solution is to add paperize.io (or possibly the individual sites, beta.editor.paperize.io, docs.paperize.io) to the "Disabled Sites" list in the Privacy Badger settings, as shown:

(🤠 hat tip to user @GodlessDevil 😈)

Other ideas:

• maybe we can detect this happening and NOT fail silently
• the "Logging in with Google..." popover could...
  • have extra info on it about this kind of thing
  • link to this theoretical help page
  • maybe add info if it takes longer than 5-10 seconds or something