Add unless command

src/vm/commands/index.ts

@@ -55,6 +55,7 @@ import {Take} from "./take.js";
 import {Group} from "./group.js";
 import {Flatten} from "./flatten.js";
 import {If} from "./if.js";
+import {Unless} from "./unless.js";
 
 export type Commands = Command<CommandData>[]
 export const commands: Commands = [
@@ -109,6 +110,7 @@ export const commands: Commands = [
     new Trim,
     new Undo,
     new Unique,
+    new Unless,
     new Unquote,
     new Upper,
     new Word,