better format CI badges in README
better format CI badges in README

[ci skip]

MengjiaoH/ospray,MengjiaoH/ospray,wilsonCernWq/ospray,ospray/OSPRay,wilsonCernWq/ospray,MengjiaoH/ospray,wilsonCernWq/ospray,MengjiaoH/ospray,ospray/OSPRay,MengjiaoH/ospray,ospray/OSPRay,ospray/OSPRay