Run completion script generation without previous setup (#386)

* Run completion script generation without previous setup

* Handle like help or init

Author: SimplyDanny

Sources/Swiftly/Proxy.swift

@@ -32,19 +32,18 @@ public enum Proxy {
 
                     if CommandLine.arguments.count == 1 {
                         // User ran swiftly with no extra arguments in an uninstalled environment, so we jump directly into
-                        //  an simple init.
+                        //  a simple init.
                         try await Init.execute(ctx, assumeYes: false, noModifyProfile: false, overwrite: false, platform: nil, verbose: false, skipInstall: false, quietShellFollowup: false)
                         return
-                    } else if CommandLine.arguments.count >= 2 && CommandLine.arguments[1] == "init" {
-                        // Let the user run the init command with their arguments, if any.
+                    } else if CommandLine.arguments.count >= 2 && ["init", "--generate-completion-script"].contains(CommandLine.arguments[1]) {
+                        // Let the user run the init command or completion script generation with arguments, if any.
                         await Swiftly.main()
                         return
-                    } else if CommandLine.arguments.count == 2 && (CommandLine.arguments[1] == "--help" || CommandLine.arguments[1] == "--experimental-dump-help") {
-                        // Allow the showing of help information
+                    } else if CommandLine.arguments.count == 2 && ["--help", "--experimental-dump-help"].contains(CommandLine.arguments[1]) {
+                        // Just print help information.
                         await Swiftly.main()
                         return
                     } else {
-                        // We've been invoked outside the "init" subcommand and we're not yet configured.
                         // This will throw if the configuration couldn't be loaded and give the user an actionable message.
                         throw err
                     }