Update deployment guides (tracking issue)

## Background
- The tutorial uses hostpath storage, which is not recommended for production environments
- The only tutorial available is for microk8s.
- No instructions on how to use ceph-csi with COS Lite.
- The cos-lite deployment step should include a note about using the offers overlay so that those are ready to be consumed when the user gets to deploying grafana-agent/cos-proxy.

## Issue tracker
- #32
- Tutorials for COS Lite using Canonical K8s
- #68
- Tutorial for COS, using s3
- #62
- Make sure tutorials end up with offers ready to use.
- https://github.com/canonical/cos-lite-bundle/issues/71
- #72
- Update the best practices doc. Clearly distinguish between COS Lite and COS.
- Update the "Migrating from LMA to COS Lite" doc:
- The guide should give example commands for consuming the CMRs from the cos mode, e.g. in grafana-agent or cos-proxy.
- “Evaluate solution parity” should include specific things to look for to confirm that COS is working
- #73
- Address ceph-csi in the "COS Lite on Canonical K8s" tutorial + reproducer ([ref](https://documentation.ubuntu.com/canonical-kubernetes/latest/charm/howto/ceph-csi/)).