docs: make setting upstream more clear, docs on npx quartz restore

Jacky Zhao

2023-08-20 d205eb568686a718cae889d51fde5ae18d352b30

 content/index.md

@@ -13,7 +13,7 @@
```shell
git clone https://github.com/jackyzha0/quartz.git
cd quartz
git checkout v4-alpha
git checkout v4
npm i
npx quartz create
```