feat(@clack/core): allow tab completion for placeholders (#146)

Author: cpreston321

.changeset/red-news-rule.md

@@ -0,0 +1,5 @@
+---
+'@clack/core': patch
+---
+
+feat(@clack/core): allow tab completion for placeholders

packages/core/src/prompts/prompt.ts

@@ -166,6 +166,12 @@ export default class Prompt {
 		if (char && (char.toLowerCase() === 'y' || char.toLowerCase() === 'n')) {
 			this.emit('confirm', char.toLowerCase() === 'y');
 		}
+		if (char === '\t' && this.opts.placeholder) {
+			if (!this.value) {
+				this.rl.write(this.opts.placeholder);
+				this.emit('value', this.opts.placeholder);
+			}
+		}
 		if (char) {
 			this.emit('key', char.toLowerCase());
 		}