Replaces the `cd frontend && npm ci` setup steps with a pnpm-flavoured
one: enable corepack (one-time), `pnpm install` from the repo root, then
`cd frontend && pnpm run <script>` for frontend scripts. misc/update.sh
also moves to `pnpm --filter mas-frontend run …`
- Removes mentions of the `mas-cli templates save` command
- Removes the old `experimental` flags
- Removes the old `policy.data.passwords` configs
- Document the `policy.data.client_registration` flags
- Remove references to the pre-built macOS binaries
- Explains how to get syn2mas
- State that you need to prepare the database before importing data
- Clean up the reverse proxy documentation
- Clarify that you don't need to provede templates/policy/assets
manually when running the docker image