Update README.md

README.md

 
 # Install
 
+OS require: build-essential libsdl1.2debian libsdl-image1.2 libsdl-image1.2-dev libsdl-ttf2.0-0 libsdl-ttf2.0-dev libsdl-mixer1.2 libsdl-mixer1.2-dev
+
 Note: OpenCombat is in development mode. 
 
 Considering in your virtual environment, install synergine2: