Support skip comment markup like # noqa

Awesome, extremely useful project, thank you!! (Just noticed I'm signed in using a GH account I created strictly for teaching purposes .. doh! My normal handle is @gavinhuttley).

### Describe the feature you'd like

I have cases where we use decorators to extend docstrings from other methods / classes, etc.. Rather than try to catch such a special case, perhaps adding support for a comment annotation (like `# noqa`, as used by linters) that indicates a method / function to be ignored?

### Is your feature request related to a problem?

Only in that methods documented in this way are not recognised as such.

### Your Environment
- `interrogate` version(s) (`interrogate --version`): 1.2.0
- Operating System(s): All
- Python version(s): 3.6+

### Additional context
None.