Enable `shift` + `J`/`K` for selecting a range of cells

[joelostblom]

In JupyterLab you can use shift + j/k just like shift + up/down arrow to select a range of cells. It would be convenient to have this in VS Code as well.

[amunger]

It seems reasonable to add this to the Jupyter Keymap extension, thanks for the suggestion.

You can also do this yourself if you add this to your keybindings.json:

    {
        "key": "shift+j",
        "command": "list.expandSelectionDown",
        "when": "listFocus && listSupportsMultiselect && !inputFocus && !treestickyScrollFocused"
    },
    {
        "key": "shift+k",
        "command": "list.expandSelectionUp",
        "when": "listFocus && listSupportsMultiselect && !inputFocus && !treestickyScrollFocused"
    }

[joelostblom]

This works great, thanks for the workaround!