No way to find out how to select next occurence (multiple cursors, ie CMD+D)

[xixixao]

Describe the bug
No way to select next occurence (you can see how this behavior works in the first animation on https://www.sublimetext.com/).

Expected behavior
Key map or command palette mentions it, let's me rebind it, there is documentation around editor commands somewhere.

Desktop (please complete the following information):

• OS: macOS Mojave
• Browser Chrome 71
• JupyterLab 0.35.4

Additional context

This is an essential editing functionality, which is supported by the underlying CodeMirror editor (afair). It's included in Sublime Text, Atom, VS Code, even traditional IDEs. It's a massive productivity boost. JupyterLab should seriously care about its text-editing experience.

[jasongrout]

This works in the text editor when the text editor keymap is set to "sublime" (see the settings menu). It appears that the notebook does not use that setting for the editor keymap, unfortunately.

[jasongrout]

A relevant comment about the notebook using the text editor keymap is at #3885 (comment).

[davidmashburn]

++ for this feature, even it it uses a different keybinding