More information about the app in README.md

[Korb]

Please add to README.md information about the methods for creating screenshots supported by the PiQture [1] and the file formats in which screenshots can be saved. Are there hotkey settings? If so, it would be great if README.md included a screenshot of the corresponding window.

[1]

1. Capture Full-screen
2. Capture Active Window
3. Capture Region
4. Capture Fixed Region
5. Capture Window Control
6. Capture Scrolling Window
7. FreeHand Capture
8. Repeat Last Capture