Add short -h option to `tail`

What does this merge request do and why?

Just a shorthand to save typing.

How to set up and validate locally

1. gdk tail -g should error out
2. gdk tail --help should show help
3. gdk tail -h should show help too

Impacted categories

The following categories relate to this merge request:

• gdk-reliability - e.g. When a GDK action fails to complete.
• gdk-usability - e.g. Improvements or suggestions around how the GDK functions.
• gdk-performance - e.g. When a GDK action is slow or times out.