Add anchors in the doc

[rom1504]

so for example it's possible to link "Complete HTML page example" in https://webtorrent.io/intro

like https://github.com/feross/webtorrent/blob/master/docs/get-started.md#complete-html-page-example

I'm not sure how it's extracted from there and rendered in webtorrent.io

ah yeah it's done with jade https://github.com/feross/webtorrent-www/blob/d5e123b00da784aeba1aa0bee53d4ccaab0daf26/server/views/intro.jade#L3 so we probably need some kind of jade setting

[feross]

👍