readme: switch to fenced code blocks
readme: switch to fenced code blocks

etdev/slim,fly19890211/slim,mojavelinux/slim,ericboehs/slim,sideci-sample/sideci-sample-slim,zakuro9715/slim,ruijsun/slim,raxoft/slim,slim-template/slim,metallurgical/slim,cheunghy/slim,raxoft/slim,XueQian/slim,slim-template/slim,mojavelinux/slim,ericboehs/slim,Nikeshsuwal/slim,zakuro9715/slim,cheunghy/slim,XueQian/slim,etdev/slim,fly19890211/slim,slim-template/slim,Nikeshsuwal/slim,metallurgical/slim,JuanitoFatas/slim,JuanitoFatas/slim,ruijsun/slim