feat: support cache resources configurable #7

[yusank]

What type of PR is this?

/kind feature

What this PR does / why we need it:

To improve performance of webhook and use less memory.

Which issue(s) this PR fixes:

Fixes #7

Special notes for your reviewer:

Does this PR introduce a user-facing change?

NONE

Additional documentation e.g., KEPs (Kubernetes Enhancement Proposals), usage docs, etc.:

Add one new args pre-cache-resources to configure which resources to cache, for example:

... // other arguments 
--pre-cache-resources=Deployment/apps/v1,Replicas/apps/v1

[likakuli]

on go files?

[yusank]

what happen? where is my code