* Add examples to clarify Host/Regular expression
Add an example to the Host section illustrating that Host not only doesn't match parent domains but also doesn't match subdomains
Add an example to Regular expression illustrating that the example regex matches substrings of the URI (because there is no end of string character)
* Revert the regex example and change the regex
Instead of adding an example to the Regular expression section to clarify that
the regex shown doesn't require the string end in google.com, let's instead
change the regex to end in a `$` and all the existing examples make a lot more
sense.