Update CHANGELOG.md
Update CHANGELOG.md

Fix formatting of the old items and add the missing mime-type bump we did in 8.8.0

juliandunn/ohai,johnbellone/ohai,acaiafa/ohai,numericillustration/ohai,tas50/ohai-1,numericillustration/ohai,juliandunn/ohai,Fodoj/ohai,acaiafa/ohai,phreakocious/ohai,phreakocious/ohai,chef/ohai,n-marton/ohai,higanworks/ohai,jaymzh/ohai,n-marton/ohai,sh9189/ohai,johnbellone/ohai,criteo-forks/ohai,sh9189/ohai,chef/ohai,jseely/ohai,criteo-forks/ohai,jaymzh/ohai,mattray/ohai,tas50/ohai-1,higanworks/ohai,jseely/ohai,Fodoj/ohai,mattray/ohai