* enable configuring storage and imap

* update docs

* Update charts/stable/maddy/Chart.yaml

Co-authored-by: Bᴇʀɴᴅ Sᴄʜᴏʀɢᴇʀs <me@bjw-s.dev>

Co-authored-by: angelnu <git@angelnucom>
Co-authored-by: Bᴇʀɴᴅ Sᴄʜᴏʀɢᴇʀs <me@bjw-s.dev>