update release notes for 2.2.1
update release notes for 2.2.1

yinjimmy/en,sdkbox-staging/en,sdkbox-staging/en,yinjimmy/en,sdkbox-staging/en,sdkbox-doc/en,sdkbox-doc/en,sdkbox-staging/en,sdkbox-doc/en,yinjimmy/en,sdkbox-doc/en,yinjimmy/en