Updated version in readme

(I always forget this!)

readme.md

@@ -2,7 +2,7 @@
 
 WLED is a fast and (relatively) secure implementation of an ESP8266/ESP32 webserver to control NeoPixel (WS2812B) LEDs!
 
-### Features: (V0.6.3)
+### Features: (V0.6.4)
 - RGB, HSB, and brightness sliders
 - Settings page - configuration over network
 - Access Point and station mode - automatic failsafe AP