Add support for global hotkeys

**Problem**
Hotkeys do not trigger when the focused element is an input or textfield.

**Suggestion**
Add opt in support for global hotkeys that fire even when focus is inside some input form/textarea. There are cases where certain shortcuts (e.g Ctrl+S to click save button, Ctrl+K to click a command palette) should work everywhere including when the user is typing in some textarea.

The feature is similar to [Mousetrap’s Global Bind](https://github.com/ccampbell/mousetrap/tree/master/plugins/global-bind).

#### Possible Implementation
Introduce a `data-hotkey-global` attribute:
```
Save
```

#### Related Work
https://github.com/github/hotkey/pull/48

Start by reading the hotkey handling entry point and the related Mousetrap Global Bind implementation linked in the issue. Check how shortcuts are suppressed for inputs and textareas, then verify that an opt-in data-hotkey-global attribute allows the requested shortcuts to trigger there without changing default behavior.

Scritto dal modello di indicizzazione a partire dal testo della issue.