Updated QRO external amplifier usage (markdown)

QRO-external-amplifier-usage.md

@@ -2,7 +2,7 @@
 
 It is possible to get 30-40% TX only coverage increase in urban environment by using additional external 1-2W amplifier (about 6$ on Aliexpress), which will give 10-12 dB signal increase, achieved approximately 20 km coverage in moderate urban environment and about 15 km with almost 100% packet receiving.
 
-- Implement simple amplifier power switching by using relay, do NOT keep this amplifier always ON
+- Implement simple amplifier power switching by using relay from one of free ESP32 pinouts, use one of popular schematics from google, do NOT keep this amplifier always ON
 - Set LoRa output power to around 8 dBm `cfg.LoraPwr = 8;`, NB! higher than 10 dBm levels can destroy amplifier
 - Set `cfg.PttEnable` to `true`
 - Set `cfg.PttPin` to your relay control pin