concise dyn-rule syntax

[Rudxain]

what if instead of

* * 3p block
github.com githubassets.com * noop
github.com githubusercontent.com * noop

we could do

* * 3p block
github.com [githubassets.com githubusercontent.com] * noop

Wiki examples:

* [ facebook.com facebook.net fbcdn.net ] * block
facebook.com [facebook.com facebook.net fbcdn.net] * noop

CDN example:

* * 3p block

* [
  akamai.net
  akamaiedge.net
  cloudflare.com
  cloudflare.net
  cloudfront.net
  edgecastcdn.net
  map.fastly.net
  jsdelivr.net
] * noop

[live.com microsoft.com] [azure.com azureedge.net] * noop