roothints: various changes

- expose the function as hints.root_file
- use the same filename as Debian
- remove the unneeded script
- docs and some nitpicks
11 jobs for <span class="ref-name">root-hints-zonefile</span> in 5 minutes and 59 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Build
failed #74193
docker linux amd64
build:linux:amd64

00:03:40

passed #48278
docker linux amd64
build:linux:amd64

00:00:31

failed #73362
docker linux amd64
build:linux:amd64

00:00:26

canceled #72858
docker linux amd64
build:linux:amd64

canceled #73187
docker linux amd64
build:linux:amd64

 
  Test
canceled #73271
docker linux amd64
deckard:linux:amd64

passed #48282
docker linux amd64
respdiff:linux:amd64

00:02:18

passed #48279
docker linux amd64
test:linux:amd64

00:00:48

passed #48281
docker linux amd64
test:linux:amd64:valgrind

00:01:04

passed #48280
docker linux amd64
deckard:linux:amd64

00:03:26

canceled #73133
docker linux amd64
deckard:linux:amd64

 
Name Stage Failure
failed
build:linux:amd64 Build There is an unknown failure, please try again
HEAD is now at cc5e14a etc/root.hints: B's IPv4 updated today
Checking out 8fa8f214 as root-hints-zonefile...
Updating/initializing submodules recursively...
Synchronizing submodule url for 'modules/policy/lua-aho-corasick'
Synchronizing submodule url for 'tests/deckard'
Synchronizing submodule url for 'tests/deckard/contrib/libfaketime'
Synchronizing submodule url for 'tests/deckard/contrib/libswrap'
Submodule path 'tests/deckard': checked out '11278dd9604cab43c25b666dec424b2f4817076a'
ERROR: Job failed (system failure): Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?