Add espduino boards

ESPDuino boards from doit.am (arduino uno look like board for esp8266)

Author: yichone

doc/filesystem.md

@@ -49,7 +49,7 @@ Olimex MOD-WIFI-ESP8266(-DEV)| 2M | 1M
 SparkFun Thing | 512k | 64k
 SweetPea ESP-210 | 4M | 1M, 3M
 WeMos D1 & D1 mini | 4M | 1M, 3M
-
+ESPDuino | 4M | 1M, 3M
 **Note:** to use any of file system functions in the sketch, add the following include to the sketch:
 
 ```c++