added setup notes

micropython_firmware/setup_notes.txt

@@ -0,0 +1,23 @@
+Flashing:
+ esptool.py --port /dev/ttyUSB0 erase_flash
+ esptool.py --port /dev/ttyUSB0 --baud 460800 write_flash --flash_size=detect 0 esp8266-20190125-v1.10.bin
+
+Setting up webrepl:
+ Connect using picocom:
+  $ picocom /dev/ttyUSB0 -b115200
+   
+  >>> import webrepl_setup
+  -> enable, set password and reboot
+
+  Connect to wifi:
+  >>> import network
+  >>> sta_if = network.WLAN(network.STA_IF)
+  >>> sta_if.active(True)
+  >>> sta_if.connect("<SSID>", "<PW>")
+  >>> sta_if.ifconfig() # this prints your IP
+
+Connect via online Webrepl:
+  -> http://micropython.org/webrepl
+ - Enter IP from above and click connect. Login with password.
+ - Upload boot.py via Webrepl to automatically connect to wifi and start webrepl after reboot
+ - You can also upload a file called main.py or just work in the webrepl terminal.