Support for multiple source paths

[padlar]

When generating docs for the operator with mutliple CRDs in different paths, it would be nice to specify multiple source paths. For ex, in the following folder structure -

api
- crd1
- crd2
- common

common contains shared structs used by both crd1 and crd2 CRDs. To generate adocs for crd1, I would have to pass folders crd1 and common. Similarly crd2 and common folders if I want docs for crd2.

I looked at the code that parses the source paths (processor/processor.go) and found out that the controller-tools has a LoadRoots api that supports reading from multiple source paths. So it shouldnt be too complex to support multiple source paths.

As a workaround to this problem, we are using config.yaml to exclude types in each adoc.