添加（111.二叉树的最小深度）：增加typescript版本

problems/0102.二叉树的层序遍历.md

@@ -2349,7 +2349,29 @@ var minDepth = function(root) {
 };
 ```
 
+TypeScript:
+
+```typescript
+function minDepth(root: TreeNode | null): number {
+    let helperQueue: TreeNode[] = [];
+    let resMin: number = 0;
+    let tempNode: TreeNode;
+    if (root !== null) helperQueue.push(root);
+    while (helperQueue.length > 0) {
+        resMin++;
+        for (let i = 0, length = helperQueue.length; i < length; i++) {
+            tempNode = helperQueue.shift()!;
+            if (tempNode.left === null && tempNode.right === null) return resMin;
+            if (tempNode.left !== null) helperQueue.push(tempNode.left);
+            if (tempNode.right !== null) helperQueue.push(tempNode.right);
+        }
+    }
+    return resMin;
+};
+```
+
 Swift：
+
 ```swift
 func minDepth(_ root: TreeNode?) -> Int {
     guard let root = root else {