添加（0344.反转字符串.md）：增加typescript版本

problems/0344.反转字符串.md

@@ -201,6 +201,27 @@ var reverseString = function(s) {
 };
 ```
 
+TypeScript：
+
+```typescript
+/**
+ Do not return anything, modify s in-place instead.
+ */
+function reverseString(s: string[]): void {
+    let length: number = s.length;
+    let left: number = 0,
+        right: number = length - 1;
+    let tempStr: string;
+    while (left < right) {
+        tempStr = s[left];
+        s[left] = s[right];
+        s[right] = tempStr;
+        left++;
+        right--;
+    }
+};
+```
+
 Swift:
 
 ```swift