New package: webhook-2.8.0

[classabbyamp]

General

• This is a new package and it conforms to the quality requirements

Have the results of the proposed changes been tested?

• I use the packages affected by the proposed changes on a regular basis and confirm this PR works for me
• I generally don't use the affected packages but briefly tested this PR

Does it build and run successfully?

(Please choose at least one native build and, if supported, at least one cross build. More are better.)

• I built this PR locally for my native architecture, (x86_64-glibc)
• I built this PR locally for these architectures (if supported. mark crossbuilds):
  • aarch64-musl (cross)
  • armv7l (cross)
  • armv6l-musl (cross)

[classabbyamp]

Which would be the best approach?

1. add the empty /etc/webhook/hooks.json
2. copy the example hooks.json to /etc/webhook
3. make_dirs="/etc/webhook 0644 root root" (what I do now)

[classabbyamp]

PR updated to add a basic default config file and set up the service to run in an unprivileged system account instead of root. @ericonr can I get a re-review on this?

[classabbyamp]

@paper42 all ready