Improve CLI helper message

[fellyph]

Describe the bug
Currently, the helper message for the accept GDPR banner is:

The path to a json file which contains selectors or button text to be used for GDPR banner acceptance

We can improve text for:

The path to a JSON file that contains selectors or button text to be used for GDPR banner acceptance

To Reproduce
Steps to reproduce the behavior:

1. Go to terminal
2. Run the command psat -h
3. See the message

Expected behavior
Update the phase to: The path to a JSON file that contains selectors or button text to be used for GDPR banner acceptance.

Screenshots

Desktop (please complete the following information):

• OS: macOS
• Version: PSAT CLI