Added docs for new filters/effects (bpf, hpf, coarse and crush)

Adds the documentation for:

* `bandq` and `bandf`
* `hresonance` and `hcutoff`
* `crush` and `coarse`

As gathered from trial-and-error as well as [this post on lurk](http://lurk.org/groups/tidal/messages/topic/37UKjz08GqgSPJyjccnfsw/) and reading the dirt code.