feat: answer TXT queries for _acme-challenge

feat: zoneOf function

fix: set NS ttl

feat: stub CNAME queries

feat: initial NS and SOA responses

feat: improve logging in parseQuery

feat: log unsupported Opcodes

feat: serve dns on tcp too

chore: update mod name and dependencies

chore: implement changes from linters, update copyright years

fix!: ignore case in queries, yikes

feat: some logging improvements

feat: dns server to fetch a records from db

refactor: directory layout