au generate should allow to specify path of generated resource

**I'm submitting a feature request**

* **Library Version:**
0.24.0

**Current behavior:**
`au generate` lets you to specify name of generator and name of resource being generated.

**Expected/desired behavior:**
`au generate` should let to specify: generator name, name of resource and *path of element*.

**What is the motivation / use case for changing the behavior?**
Current setup works well if default project organization is being used (resources grouped by resource type) it will not work however for custom setups like grouping resources by feature which is very useful for bigger projects.