Some Org-mode key bindings (contains <return>) did not work as expected

### Checklist

- [x] Using latest version on the [App Store](http://itunes.apple.com/app/id1156707581)
- [x] Read the [docs](http://blink.sh/docs/)
- [x] Searched for [existing GitHub issues](https://github.com/blinksh/blink/issues)

### Configuration

[Option] AS [Escape] in Blink, iPad Pro 10.5 with Smart Keyboard.

### Describe the bug

Under Org-mode Emacs (Spacemacs):
1. Hit OPTION+return will insert a new heading, this is correct.
2. Hit CTRL+return will enter a newline: should insert a new heading at the end of the current subtree.
3. Hit CTRL+SHIFT+return will enter a newline: should insert new TODO entry with same level as current heading.
4. Hit OPTION+SHIFT+return will insert a new heading: should insert new TODO entry with same level as current heading.

Above behaviours are same under iTerm, unless I toggle "Report modifiers using CSI u" under Profiles->Keys. After I toggle that, only 4. OPTION+SHIFT+RETURN will not work, it will only insert a letter "u".

I am not sure whether this is a bug or a feature need to implement. If this can be implement by "Custom Presses", I would love to know how. I am also wondering if anyone know why 4. OPTION+SHIFT+RETURN does not work under iTerm.

Start by reproducing the Org-mode key bindings on the stated iPad Pro with Smart Keyboard, comparing normal behavior with the “Report modifiers using CSI u” setting and Custom Presses. Done means OPTION/CTRL plus RETURN produce the expected Org-mode actions rather than a newline or the letter “u”.

Written by the indexing model from the issue text.