Add Docs for v1 APIs

[ddebroy]

What type of PR is this?

Uncomment only one /kind <> line, hit enter to put that in a new line, and remove leading whitespaces from that line:

/kind api-change
/kind bug
/kind cleanup
/kind design

/kind documentation

/kind failing-test
/kind feature
/kind flake

What this PR does / why we need it:
Add more readable documentation for the v1 API groups

Special notes for your reviewer:
Docs generated using protoc-gen-doc + some manual fixups to align it with what we want. TODO: make the protoc-gen-doc generate what we want and make that a Makefile target.

csi-proxy % docker run --rm -v $(pwd)/docs/apis:/out -v $(pwd)/client/api/smb/v1:/protos pseudomuto/protoc-gen-doc --doc_opt=markdown,smb_v1.md

Does this PR introduce a user-facing change?:

NONE

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: ddebroy

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[ddebroy]

/sig docs

[jingxu97]

/lgtm