add PPM output option

[axljackass]

any interest in adding PPM output instead of PWM?
a lot of us still have old flight controllers like APM,mini APM,CC3D and alikes which can be use with PPM inputs only.
although these are old flight controllers but i believe they are all still well capable and stable, the only missing right now is the converter CRSF to PPM output.
Hopefully can bring back these old flight controllers in service with your CRSF to PPM output converter.

thanks.

[CapnBry]

Not from me I'm afraid. I don't have any hardware that requires PPM, and PPM is a wholly different system from servo PWM. Maybe someone would want to write it as an example for the CrsfSerial library, but it doesn't interest me so it probably will not be me.