Localize assets

### Related to a problem?

_No response_

### Describe the solution you'd like

```md
![example](example.png "This is an example")
```

Should locate and load `example.fr.png` if current page language is `fr`.

```
assets
├─ example.fr.png
└─ example.png
pages
├─ index.fr.md
└─ index.md
```

### Describe alternatives you've considered

_No response_

### Additional context

_No response_