maybe a typo of the README?

[Hezhexi2002]

@geerlingguy Hi,really thanks for your great work,but there seems a typo in your current typo which may cause execution failed of ansible-playbook main.yml,In that case,the argument should be -k instead of the -K mentioned in your README,hope you can check this out and correct it in a update README.

[geerlingguy]

Fixed it in the README, thanks!