Markdown can be displayed, but rst cannot be displayed

### Description

ReadME.rst cannot be displayed

### Gitea Version

 1.24.4

### Can you reproduce the bug on the Gitea demo site?

Yes

### Log Gist

_No response_

### Screenshots

ReadME.rst cannot be displayed

### Git Version

_No response_

### Operating System

_No response_

### How are you running Gitea?

ReadME.rst cannot be displayed

### Database

None