Community maintained Docker config for the knot server

Switch from using `master` branch to using tagged release #60

Merged anirudh.fi
targeting main from deleted fork:change-to-tagged-release
Merged opened by and assigned to anirudh.fi
targeting main from deleted fork:change-to-tagged-release

This PR changed the Dockerfile and docker-compose.yml to target a stable release rather than the master/latest commit.

Resolves: #59


Currently, the Dockerfile pulls the latest master branch from the upstream tangled.org/core repository.

Now that the overhauled rust knot v1.20.0 is out, we should switch to using tagged releases instead of pulling from master to provide a more stable build experience for individuals who may be building the container themself.

There is still the option to override the tag (as outlined in the README) so those who intentionally choose to build off master can continue to do so.

Commits 0