Support reddit.com/s urls

[pfgithub]

Reddit shortlinks/sharelinks go here now so lots of links in comments are broken

s link example http://localhost:3004/#https://www.reddit.com/r/TheoryOfReddit/comments/1b4tdjb/whats_with_the_s_links/

[pfgithub]

May not be possible without an extension:

• new reddit has migrated off of react and no longer exposes clientside routing in the same way (they still have it somewhat, but putting a random url in history and going back() to it doesn't do anything)
• new reddit opens these in a new tab and does not go through any clientside logic
• these links maybe can only be generated on mobile
• response headers from the redirected page have some interesting information, but we can't it because of cors

[pfgithub]

Tried using an iframe. It looked promising from the console but it is blocked by CSP. This needs to go in the extension unfortunately unless there's some API for it.