feat(ynab): add goal completed trigger

packages/docs/pages/apps/you-need-a-budget/triggers.md

@@ -3,6 +3,8 @@ favicon: /favicons/you-need-a-budget.svg
 items:
   - name: Category overspent
     desc: Triggers when a category exceeds its budget, resulting in a negative balance.
+  - name: Goal completed
+    desc: Triggers when a goal is completed.
   - name: Low account balance
     desc: Triggers when the balance of a Checking or Savings account falls below a specified amount within a given month.
 ---