Support multiple URLs in the "When URL contains" field

[Terrance]

As far as I can tell, only a single URL substring is supported per rule, unlike the shared URL patterns field which takes a semicolon-separated list. It would be useful to do this per-rule too so that I don't have to duplicate a number of rules across multiple domains.

[nukeop]

Same. I thought the interface must be wrong, but there really is no way to apply different rules to different sites.