[Shortcut Guide] Add shortcut taskbar for Task View / Cortana / Widget

[LRitzdorf]

Summary of the enhancement

This issue details two small update suggestions to the Shortcut Guide PowerToy.

The first update would move the "Open Task view" tip to just above the taskbar, where the number-key tips currently appear.

The second update would add a "C - Open Cortana" tip above the Cortana button on the taskbar, in the same row as the number-key tips.

These suggestions are illustrated below:

In addition, I am aware that users can customize the taskbar by removing one or both of these buttons. In that case, the tips should probably be moved back to the standard location (in the middle of the screen).