Fix typos/grammar in CONTRIBUTING.MD (#8272)
Fix typos/grammar in CONTRIBUTING.MD (#8272)


svivian/Pokemon-Showdown,xfix/Pokemon-Showdown,svivian/Pokemon-Showdown,Zarel/Pokemon-Showdown,xfix/Pokemon-Showdown,xfix/Pokemon-Showdown,svivian/Pokemon-Showdown,Zarel/Pokemon-Showdown,Zarel/Pokemon-Showdown,xfix/Pokemon-Showdown,svivian/Pokemon-Showdown,svivian/Pokemon-Showdown,xfix/Pokemon-Showdown