Editing the code should not pass events to slidev

[peekxc]

Shortcut keys are passed as-is if you actually try to edit the code. These should be prevented.

For example, the d key by default toggle the presentation between light and dark mode, thus if you enter d while editing code live during the presentation, the whole slide deck will switch between light and dark. Same goes for any shortcut key, like f for full screen.

[kermanx]

Does this happen in Slidev without this addon? For example,

```ts {monaco-run}
testtest
```

and

```ts {monaco}
testtest
```