fix(README): document .depth for TreeNode

sbesselsen · sbesselsen · commit 16306176be85 · 2019-11-05T15:17:53.000+01:00
diff --git a/README.md b/README.md
@@ -141,6 +141,7 @@ Root element properties:
 * `isExpanded: boolean`
 * `isActive: boolean`
 * `isActiveTrail: boolean`
+* `depth: number`
 * `children: Tree<T>`
 
 ## Typescript
