Add cmd line parser (#512)

This commit adds the clap library and configures the necessary args to
parse from the command line,  expanding the current option of a single
file and adding support for environment variables.

Signed-off-by: Sebastian Webber <sebastian@swebber.me>

Cargo.toml

@@ -46,6 +46,7 @@ trust-dns-resolver = "0.22.0"
 tokio-test = "0.4.2"
 serde_json = "1"
 itertools = "0.10"
+clap = { version = "4.3.1", features = ["derive", "env"] }
 
 [target.'cfg(not(target_env = "msvc"))'.dependencies]
 jemallocator = "0.5.0"