9728. Custom Domain for My Personal Website - Draft

Upgrade bootstrap from 3 to 4 for jojozhuang.github.io.

1. Difference between 3 and 4

I Register a domain jojozhuang.github.io for my personal website. Now, you can visit it through jojozhuang.github.io. When user visits the original jojozhuang.github.io, they will be redirected to jojozhuang.github.io automatically.

3. References