TinySQL suggestions on document writing

[DylanYangYuchen]

1. write this in the home page of tinySQL: You are advised to use Linux instead of Windows
2. Project1: explains in more detail on how to test: Clone the project, go to the project directory and run Go Test xxxxx
3. Project2: write this prompt in the .md file of project 2: After each modification of the . y file, first make parser and then runs the test function
4. Project3: The brief introduction of the schema change paper is too brief. There is a link on Zhihu to interpret the paper which you can recommend reading it. Example like: https://zhuanlan.zhihu.com/p/309831009. It is neither too brief nor too tedious.
5. project4: TinySQL's Prerequisit doesn't say you need to learn the optimizer ahead of time. But Project4 went straight to the introduction of the optimizer in TiDB, which was confusing. Please tell beginners what to learn to pass it.