Update README.md
Update README.md
Spectrum analyser mode in RX too. Short ch6 output to GND to enable it.
Add spectrum analyser descrtiption.
PPM is selected by either
1) connect MOSI to GND (on the AVRISP connector on OrangeRX receiver)
  - in this mode outputs CH1-CH4 = channel 1-4, CH5 = PPM, CH6-CH8 = channel 5-7
2) connect CH7-CH7 using a jumpper
  - in this mode outputs CH1-CH4 = channel 1-4, CH5 = PPM, CH6 = channel 5

To force binding on RX connect jumpper on CH1-CH2

To make RX act as openLRS spectrum analyser put a jumpper on CH3-CH4, LEDs stay dark in this mode.

It is now possible to disable to "always bind" feature in the openLRSng.ino
Merge branch 'master' of https://github.com/kh4/openLRSng
style fix
README update with new jumpper settings.
Correct the combined mode (AVRISP is shared with CH6-8). 6 channels are available in combined mode as PWM.
Fixed "forced bind" in README.
Add FORCED_PPM_OUTPUT define to make it possible to have 7 PWM channels in combined mode.
Merge branch 'master' of https://github.com/kh4/openLRSng
style
Add helpper for US FRS channels (beacon)
Typos and some grammar fixes
Merge pull request #9 from pwarren/master

Fixed some typos
RX: change RSSI PWM frequency to 32kHZ (from 500Hz)
RX: drop analogWrite usage and use timer directly for RSSI.
format
Fixup README