Link to the BIND 9 repository with the script for automated DNS Shotgun
evaluation, as it might be useful to a wider audience of users
attempting to do similar performance testing/monitoring.

Slightly reduce to default chart size

See merge request !99

Also change the default to improve readability.

Tweak the chart size to provide a better font to figure size ratio and
make the resulting charts more readable.

Ignore SIGPIPE to avoid crash on broken connections

See merge request !98

Correctly reset DNS objects in filter-dnsq

See merge request !94

Dnsjit API requires explicit :reset() call on objects which make use of
more than DNS packet header. The new API was added only in dnsjit 1.3.0.

Fix installation instructions

See merge request !96

Newer versions of dnsjit no longer ignore all signals sent to the
process. We need to ensure that SIGPIPE caused by a single broken
connection won't cause shotgun to end abruptly.

Related https://github.com/DNS-OARC/dnsjit/issues/234

Split Dockerfile to build and runtime phases to cut down image size

See merge request !95

Release v20240219

See merge request !92

Support for DNS-over-QUIC

Closes #22

See merge request !75

Unfortunately, we are not yet able to detect the misconfiguration [1]
ourselves, so when `%NO_TICKETS` is set in the priority string,
`zero_rtt` also needs to be explicitly set to `false`, otherwise Shotgun
misbehaves.

[1] See GnuTLS mailing list: <https://lists.gnutls.org/pipermail/gnutls-help/2024-January/004844.html>

This merges the two counters into conn_handshakes, as they are mutually
exclusive anyway. Configuration can still refer to 'tcp_hs' for
compatibility, but the preferred way is now 'conn_hs'. Note that
'tcp_hs' will also work for QUIC.