docs: update changelog for 0.2.1
docs: update changelog for 0.2.1

sbuettner/kong,paritoshmmmec/kong,peterayeni/kong,wakermahmud/kong,puug/kong,chourobin/kong,ChristopherBiscardi/kong,AnsonSmith/kong,vmercierfr/kong,skynet/kong,bbalu/kong,Skyscanner/kong