Minor cleanup on CONTRIBUTING.md
Minor cleanup on CONTRIBUTING.md

1ace/sway,sleep-walker/sway,4e554c4c/sway,mikkeloscar/sway,taiyu-len/sway,1ace/sway,ascent12/sway,ascent12/sway,mikkeloscar/sway,ascent12/sway,taiyu-len/sway,4e554c4c/sway,1ace/sway,taiyu-len/sway,SirCmpwn/sway,sleep-walker/sway,ptMuta/sway,johalun/sway