Documentation update

Now that KubePlus has deprecated support defining and enforcing Pod-level policies, we need to update our documentation to remove references of Pod-level policies. We need to update the ResourceComposition specification to remove the `podconfig` specification.

Here are such places where it is still remaining are the following:
https://cloud-ark.github.io/kubeplus/docs/html/html/sample-example.html
https://cloud-ark.github.io/kubeplus/docs/html/html/kubeplus-components.html

Also, update the ResourcePolicy discussion.

We should also go through [all the doc pages](https://cloud-ark.github.io/kubeplus/docs/html/html/index.html) and bring it up-to-date as required.