Add some description to README.md

Author: bdesterBE

README.md

@@ -1,4 +1,15 @@
 # LoRaMac-node-esp32
-ESP32 port of LoRaMac-node
+#### ESP32 port of LoRaMac-node
+Creates an ESP32 component that pulls in all LoRaMac-node sources allowing for a custom ESP32 board definition to be used.
 
-This is work in progress - not usable yet
+## Compatibility
+This library is written for and is currently only compatible with Semtech SX126x LoRaWAN chips.
+
+## Configuration
+- Running menuconfig with LoRaMac-node-esp32 added as a component will allow for configuration of SPI pins and the host to be used.
+- Region(s) of operation must be selected by pulling in one of the pre-processor definitions used by LoRaMac-node, e.g. `REGION_US915`.
+  - Regions are listed in `src/LoRaMac-node/src/mac/region/Region.h`
+
+## Notes
+- `SX126xWaitOnBusy()` indefinitely blocks with a busy wait, waiting for a low BUSY signal 
+- This is work in progress - not usable yet