This new member of `Flag` indicates if the flag expects a file as input.
This is especially useful for documentation and shell completion purposes.
Signed-off-by: Sascha Grunert <sgrunert@suse.com>
This adds two new methods to the `App` struct:
- `ToMarkdown`: creates a markdown documentation string
- `ToMan`: creates a man page string
Signed-off-by: Sascha Grunert <mail@saschagrunert.de>