docs: fix '--verbose' option typo

[xeader]

I fixed the wrong option for verbose output

Closes issue:

Reviewer checks

Required fields, to be filled out by PR reviewer(s)

• [x] Follows the commit message policy, appropriate for next version
• [x] Code is reviewed for security

[claassistantio]

All committers have signed the CLA.

[straker]

Thanks for the fix.

[straker]

@xeader So CircleCI seems to have not even started a test build for this pr. Could you push an empty commit to see if that retriggers CircleCI? git commit -m "empty commit to trigger build" --allow-empty

[stephenmathieson]

For some reason, CircleCI was told to not build forks (screen shot below):

I've changed this and pushed a new commit.