Update the information architecture for the v4 docs

[paigecalvert]

As originally proposed and approved in https://github.com/helm/community/blob/main/hips/hip-0024.md, perform a content audit and design a new information architecture that is more intuitive, reflects common workflows for the different Helm user personas, improves content find-ability, and aligns with tech comm standards.

Follow the CNCF techdocs analysis to complete the docs audit, and use the criteria to inform organizational decisions: https://github.com/cncf/techdocs/blob/main/docs/analysis/howto.md

This issue is to be done after https://github.com/helm/helm-www/issues/1862

Follow-up issues should be created to track the work for implementing the re-org.