[orca-list] List Shortcuts mode should display keyboard shortcuts on the screen.

[Dattatray Bhat <bhatdv gmail com>]

In List Shortcuts mode, Orca provides a list of available keyboard shortcuts. A user can navigate the list using Up/ Down arrow keys. Orca speaks and brailles the list item under focus, one at a time. This navigation is not convenient for low vision users. If the list is displayed on screen, the low vision users need not wait for each item to be spoken or brailled. They can read the items on the screen and move through the list much faster.

Dattatray Bhat
C-DAC Mumbai