Additional clarifications for tasks/readme

hm, having looked a bit closer, what I say here isn't correct, because non-class namespaces aren't 'exportable' (they aren't in info.json), so will produce an error if listed here. So I will rewrite this.

What I meant was that class namespace 'exports' in the case of simple/whitespace are as in OL2: just a list of which classes/namespaces you use. The methods won't be renamed/optimized, so they will all be 'exported', whether you list them or not.