Update README.markdown
Update README.markdown

added build status image
peq/WurstScript,Crigges/WurstScript,Crigges/WurstScript,peq/WurstScript,Crigges/WurstScript,Crigges/WurstScript,Crigges/WurstScript,Cokemonkey11/WurstScript,Cokemonkey11/WurstScript,Crigges/WurstScript,wurstscript/WurstScript,wurstscript/WurstScript,peq/WurstScript,wurstscript/WurstScript,Cokemonkey11/WurstScript,Cokemonkey11/WurstScript,Cokemonkey11/WurstScript,Crigges/WurstScript,peq/WurstScript,Crigges/WurstScript