Describe the bug
Non friendly error message when passing wrong values in the cmd-line.

To Reproduce
Steps to reproduce the behavior:

oasdiff changelog data/common-params/params_in_path.yaml data/common-params/params_in_op.yaml --flatten-params=x

Outputs:

Error: invalid argument "x" for "--flatten-params" flag: strconv.ParseBool: parsing "x": invalid syntax

Expected behavior
Message shouldn't mention strconv.ParseBool

Desktop (please complete the following information):

• OS: macos