style: format code and docs with prettier

Author: yanglbme

lcof/面试题53 - II. 0～n-1中缺失的数字/README.md

@@ -188,7 +188,7 @@ class Solution {
     func missingNumber(_ nums: [Int]) -> Int {
         var left = 0
         var right = nums.count
-        
+
         while left < right {
             let mid = (left + right) / 2
             if nums[mid] > mid {