Updated arduino-esp8266fs-plugin link to 0.3.0 (#2846)

Author: bsilvereagle

doc/filesystem.md

@@ -81,7 +81,7 @@ For more details on the internals of SPIFFS implementation, see the [SPIFFS read
 
 *ESP8266FS* is a tool which integrates into the Arduino IDE. It adds a menu item to *Tools* menu for uploading the contents of sketch data directory into ESP8266 flash file system.
 
-- Download the tool: https://github.com/esp8266/arduino-esp8266fs-plugin/releases/download/0.2.0/ESP8266FS-0.2.0.zip.
+- Download the tool: https://github.com/esp8266/arduino-esp8266fs-plugin/releases/download/0.3.0/ESP8266FS-0.3.0.zip.
 - In your Arduino sketchbook directory, create `tools` directory if it doesn't exist yet
 - Unpack the tool into `tools` directory (the path will look like `<home_dir>/Arduino/tools/ESP8266FS/tool/esp8266fs.jar`)
 - Restart Arduino IDE