Brute force attack protection settings: verbiage enhancements

**Current:**

**Proposed:**

Description
> Brute force attacks are the most common form of hacking. Using large networks of computers, bots try to gain access to your site by using different combinations of usernames and passwords until they find the right one. Jetpack automatically blocks these attacks, protecting your WordPress site from unauthorized access.

@benhuberman my description is a little long, but I think it's fairly short given the fact we have to explain a pretty complex thing. Thoughts on making it a bit more concise?

Toggle:
> Enable brute force attack protection

> Whitelisting
> Whitelisting an IP address will prevent it from ever being blocked by Jetpack. You can whitelist multiple IP addresses like your home, office, and more to make sure you'll always be able to get into your site.