feat: compile time completion generation

Removed `completion` command in favor of compile time completion
generation. This tool will only be build from source for the foreseeable
future so this makes sense for now.

src/cli/ahab.rs

@@ -1,6 +1,5 @@
 use super::{Django, Docker, DockerCompose, Postgres};
 use clap::{Parser, Subcommand};
-use clap_complete::Shell;
 
 /// A program for interacting with various dockerized applications.
 #[derive(Parser, Debug)]
@@ -12,12 +11,6 @@ pub struct Ahab {
 
 #[derive(Debug, Subcommand)]
 pub enum Commands {
-    /// Generate completion files
-    Completion {
-        #[arg(value_enum)]
-        shell: Shell,
-    },
-
     /// Docker related subcommands
     Docker {
         #[command(subcommand)]