update api

README.md

@@ -5,13 +5,13 @@ A simple and lightweight database written in C
 Most part of this README and the docs in `api` folder is written in Chinese. If you want to use it but have any problem in language, please contact me directly through the issues.
 
 ## 支持的功能
-- [ ] 创建[数据库文件](/api/dbfile.md#数据库文件格式)和[表](/api/dbfile.md#新建表)
-- [ ] [删除表](/api/dbfile.md#删除表)
-- [ ] [插入表项](/api/table.md#表项)
-- [ ] [删除表项](/api/table.md#表项)
+- [ ] 创建[数据库文件](/api/dbfile.md#数据库文件格式)和[表](/api/dbfile.md#表)
+- [ ] 删除表
 - [ ] 对主键、外键进行[索引](/api/index.md)
+- [ ] [插入表项](/api/table.md#表项的增加)
+- [ ] 按索引修改表项
+- [ ] 按索引[删除表项](/api/table.md#表项的删除)
 - [ ] 对非主键（无[unique约束](/api/types.md#类型修饰符)）进行[索引](/api/index.md)
-- [ ] 修改表项
 
 ## Thanks
 - [asciiflow](https://asciiflow.com/)