refactor(odin): Migrated nushell-completion command to go.

main.odin

@@ -32,6 +32,8 @@ main :: proc() {
 		cmd_scan(&cmd)
 	case "sync":
 		cmd_sync(&cmd)
+	case "nushell-completion":
+		cmd_nushell_completion(&cmd)
 	case:
 		fmt.printf("Unknown command: %s\n", cmd.name)
 		print_usage()