feat: api endpoint to update a record

fix: DNS pattern in the ui, following the previous commit

docs: fix doc about dots in domain pattern

feat: dns server to fetch a records from db

feat: check that domains are only ascii letters and numbers

feat: don't allow full stops in domains

feat: ability to update user email and password, and delete user

fix: typo in error

fix: login should use normal base

refactor: backend -> api, move routers

refactor: move more to handlers

refactor: directory layout