Show context in detail pages

[cweiske]

The old chatlog would show some lines of context around the current line in the detail view. The new one should to this, too.

Example: http://indieweb.org/irc/2017-05-25/line/1495767292371

[aaronpk]

Depends on aaronpk/QuartzDB#2

[bkil]

It would also help as a minimal viable product if each search hit or detail page had an additional link that points to the path of the given channel and date and include the timestamp in the anchor as well (i.e., to jump on the message).