Create a Blackbox comparison template for dterm_lpf2_hz tests

[19379353560]

A comparison template would help testers report useful data instead of vague impressions.

Useful fields:

• aircraft type and size
• firmware commit
• PID/filter profile
• dterm_lpf2_hz value
• D-term noise notes
• gyro noise notes
• motor temperature notes
• links or attachments for logs/screenshots

Related flight-test request: #1

[19379353560]

Related technical note for anyone preparing a comparison template:

https://19379353560.github.io/dterm-prefilter-technical-note.html

The key comparison remains one frame and one tune, changing only dterm_lpf2_hz: disabled, 200Hz, and 250Hz when possible.