feat: add solutions to lc problems: No.2287~2290

* No.2287.Rearrange Characters to Make Target String
* No.2288.Apply Discount to Prices
* No.2289.Steps to Make Array Non-decreasing
* No.2290.Minimum Obstacle Removal to Reach Corner

Author: yanglbme

README.md

@@ -86,6 +86,7 @@
 -   [访问所有节点的最短路径](/solution/0800-0899/0847.Shortest%20Path%20Visiting%20All%20Nodes/README.md) - `BFS`、`最小步数模型`、`A* 算法`
 -   [为高尔夫比赛砍树](/solution/0600-0699/0675.Cut%20Off%20Trees%20for%20Golf%20Event/README.md) - `BFS`、`A* 算法`
 -   [使网格图至少有一条有效路径的最小代价](/solution/1300-1399/1368.Minimum%20Cost%20to%20Make%20at%20Least%20One%20Valid%20Path%20in%20a%20Grid/README.md) - `双端队列 BFS`
+-   [到达角落需要移除障碍物的最小数目](/solution/2200-2299/2290.Minimum%20Obstacle%20Removal%20to%20Reach%20Corner/README.md) - `双端队列 BFS`
 -   [迷宫](/solution/0400-0499/0490.The%20Maze/README.md) - `DFS`、`连通性模型`、`Flood Fill 算法`
 -   [单词搜索](/solution/0000-0099/0079.Word%20Search/README.md) - `DFS`、`搜索顺序`、`回溯`
 -   [黄金矿工](/solution/1200-1299/1219.Path%20with%20Maximum%20Gold/README.md) - `DFS`、`搜索顺序`、`回溯`

README_EN.md

@@ -84,6 +84,7 @@ Complete solutions to [LeetCode](https://leetcode.com/problemset/all/), [LCOF](h
 -   [Shortest Path Visiting All Nodes](/solution/0800-0899/0847.Shortest%20Path%20Visiting%20All%20Nodes/README_EN.md) - `BFS`, `Minimum steps model`, `A* search`
 -   [Cut Off Trees for Golf Event](/solution/0600-0699/0675.Cut%20Off%20Trees%20for%20Golf%20Event/README_EN.md) - `BFS`, `A* search`
 -   [Minimum Cost to Make at Least One Valid Path in a Grid](/solution/1300-1399/1368.Minimum%20Cost%20to%20Make%20at%20Least%20One%20Valid%20Path%20in%20a%20Grid/README_EN.md) - `BFS using deque`
+-   [Minimum Cost to Make at Least One Valid Path in a Grid](/solution/2200-2299/2290.Minimum%20Obstacle%20Removal%20to%20Reach%20Corner/README_EN.md) - `BFS using deque`
 -   [The Maze](/solution/0400-0499/0490.The%20Maze/README_EN.md) - `DFS, Flood fill`
 -   [Word Search](/solution/0000-0099/0079.Word%20Search/README_EN.md) - `DFS`, `Backtracking`
 -   [Path with Maximum Gold](/solution/1200-1299/1219.Path%20with%20Maximum%20Gold/README_EN.md) - `DFS`, `Backtracking`