Packaging Caddy for Debian

Description of the project: Caddy is a modern webserver written in Go which doesn't bring the historical debts of Apache2 or Nginx. It has HTTPS enabled per default and Let's Encrypt support. Unfortunately, Caddy is not available as a Debian package yet. Quite a few Go dependency libraries are missing as well. So far, fetching a pre-compiled binary from Github is the only non-developer option to install Caddy on Debian. The goal of this Project is to change this by packaging Caddy and all required dependencies for Debian. The package should be reproducible and have continuous automated testing both in Salsa CI and via autopkgtests. As a result, we would get a reproducible binary that is built on trusted infrastructure and secures against supply chain attacks.