build(docker): Expose mailhog port.
build(Docker): Improve wording.
build(docker): Mailhog and network changes.
* Add mailhog container to shared network to enable connectivity
* Configure project name for docker compose in .env sample file,
without it the basename of the repo directory is used, which
makes it unreachable for other services
* Set mailhog host to mailhog (instead of localhost) if MAILHOG_HOST
env var is set
* Expose 1025 to enable local troubleshooting
build(docker): Update README to reflect compose changes.
Otto Jongerius