Create ability to ignore default PII scanning patterns

[JordoHeffernan]

As a user, I want to be able to stop secureli from scanning for the default PII patterns

AC

1. Add item to .secureli.yaml called ignore-pii-patterns
2. ignore-pii-patterns can only accept 'email', 'ssn', 'phone'
3. if one of these items is included in the secureli congif, ignore that category when the PII scan runs
   a. if there are any items in ignore-pii-patterns beyond the acceptable list, throw an error.
4. add ability to put new items into config via cli, either with a new flag on an existing command or a new command
   a. confirm user's input fits acceptable items, throw an error if it does not
5. Add note in documentation to notify users of functionality

[blonienc]

This was completed in #558.