0018b0a15e
Changes: 1. Use uniform links types relative to doc folder (start with `doc/`) 2. According to [docusaurus links](https://docusaurus.io/docs/markdown-features/links), if `<a>` is used, the `href` is resolved as URL location, but not file location. So need to use `[text]({{< relref "path" >}})` instead.