Conceal comments

### Issues

- [X] I have checked [existing issues](https://github.com/vhyrro/neorg/issues?q=is%3Aissue) and there are no existing ones with the same request.

### Feature description

Conceal

`%inline comments%`

and

```norg
#comment
block comments
that may span across lines
```

### Help

Yes

### Implementation help

_No response_