docs: update README.md

Author: yanglbme

README.md

@@ -19,12 +19,13 @@ Complete solutions to [LeetCode](https://leetcode-cn.com/problemset/all/), [LCCI
 
 [中文文档](./README_CN.md)
 
-## Solution Tree
+## Solutions
 - [LeetCode](./solution/README.md)
 - [LCCI](./lcci/README.md) / [LCOF](./lcof/README.md)
 
 ## Contributions
 I'm looking for long-term contributors/partners to this repo! Send me [PRs](https://github.com/doocs/leetcode/pulls) if you're interested! See the following:
+
 - <kbd>Fork</kbd> [this repository](https://github.com/doocs/leetcode) to your own GitHub account and then <kbd>clone</kbd> it to your local machine.
 - Make some changes to your leetcode repository, then <kbd>add</kbd>, <kbd>commit</kbd> and <kbd>push</kbd> the changes to your remote GitHub repository.
 - Submit a pull request with your changes!
@@ -44,4 +45,4 @@ This project exists thanks to all the people who contribute.
 <a href="https://opencollective.com/doocs-leetcode/contributors.svg?width=890&button=true"><img src="https://opencollective.com/doocs-leetcode/contributors.svg?width=890&button=false" /></a>
 
 ## License
-<a rel="license" href="https://github.com/doocs/leetcode/blob/master/LICENSE"><img alt="Creative Commons License" style="border-width:0" src="./img/cc-by-sa-88x31.png" /></a><br />This work is licensed under a <a rel="license" href="http://creativecommons.org/licenses/by-sa/4.0/">Creative Commons Attribution-ShareAlike 4.0 International License</a>.
+<a rel="license" href="https://github.com/doocs/leetcode/blob/master/LICENSE"><img alt="Creative Commons License" style="border-width:0" src="./img/cc-by-sa-88x31.png" /></a><br />This work is licensed under a <a rel="license" href="http://creativecommons.org/licenses/by-sa/4.0/">Creative Commons Attribution-ShareAlike 4.0 International License</a>.

README_CN.md

@@ -46,5 +46,4 @@
 <a href="https://opencollective.com/doocs-leetcode/contributors.svg?width=890&button=true"><img src="https://opencollective.com/doocs-leetcode/contributors.svg?width=890&button=false" /></a>
 
 ## 许可证
-
-<a rel="license" href="https://github.com/doocs/leetcode/blob/master/LICENSE"><img alt="Creative Commons License" style="border-width:0" src="./img/cc-by-sa-88x31.png" /></a><br /><a rel="license" href="http://creativecommons.org/licenses/by-sa/4.0/">知识共享 版权归属-相同方式共享 4.0 国际 公共许可证</a>。
+<a rel="license" href="https://github.com/doocs/leetcode/blob/master/LICENSE"><img alt="Creative Commons License" style="border-width:0" src="./img/cc-by-sa-88x31.png" /></a><br /><a rel="license" href="http://creativecommons.org/licenses/by-sa/4.0/">知识共享 版权归属-相同方式共享 4.0 国际 公共许可证</a>。

lcof/面试题27. 二叉树的镜像/README.md

@@ -22,7 +22,6 @@
  / \   / \
 9   6 3   1
 ```
- 
 
 **示例 1：**