Add prominent tooltip for region Ctrl modifier
## Submitted by Yousuf Philips `@philipzae`
Assigned to **Xfce Bug Triage**
**[Link to original bug (#16513)](https://bugzilla.xfce.org/show_bug.cgi?id=16513)**
## Description
Only after watching the screenshot animation on the 4.14 tour page did I learn that the region option has the ability using Ctrl to move the selection around and in order to make this more discoverable, a tooltip needs to be added to the dialog.
issue