Make notch filter configuration more discoverable

#### Issue details
notch filter configuration is not discoverable

#### Version
latest

#### Platform
[ x] All
[ ] AntennaTracker
[ ] Copter
[ ] Plane
[ ] Rover
[ ] Sub

I think it should have a screen in the "Optional Hardware" list. and it would be nice if that screen had a link to the wiki documentation as well

Start by locating the Optional Hardware list and comparable configuration screens in Mission Planner. Confirm where notch-filter settings are exposed and which wiki documentation should be linked; done means the screen is discoverable there and opens the relevant documentation on all platforms.

Written by the indexing model from the issue text.