update how to release doc (#8590)
update how to release doc (#8590)

* update how to release docs for staged website, updated email templates with checksums and docker

* fix typo

* review stuff

* review stuff

* hmm

* nope

leventov/druid,Fokko/druid,pjain1/druid,nishantmonu51/druid,himanshug/druid,implydata/druid,druid-io/druid,monetate/druid,Fokko/druid,deltaprojects/druid,himanshug/druid,leventov/druid,Fokko/druid,gianm/druid,nishantmonu51/druid,Fokko/druid,implydata/druid,pjain1/druid,deltaprojects/druid,gianm/druid,monetate/druid,Fokko/druid,leventov/druid,nishantmonu51/druid,monetate/druid,gianm/druid,pjain1/druid,gianm/druid,mghosh4/druid,jon-wei/druid,deltaprojects/druid,druid-io/druid,implydata/druid,monetate/druid,himanshug/druid,himanshug/druid,gianm/druid,leventov/druid,druid-io/druid,Fokko/druid,jon-wei/druid,mghosh4/druid,jon-wei/druid,druid-io/druid,nishantmonu51/druid,deltaprojects/druid,mghosh4/druid,deltaprojects/druid,pjain1/druid,pjain1/druid,nishantmonu51/druid,pjain1/druid,mghosh4/druid,jon-wei/druid,Fokko/druid,gianm/druid,gianm/druid,mghosh4/druid,pjain1/druid,mghosh4/druid,monetate/druid,implydata/druid,nishantmonu51/druid,druid-io/druid,implydata/druid,monetate/druid,jon-wei/druid,leventov/druid,deltaprojects/druid,jon-wei/druid,implydata/druid,monetate/druid,jon-wei/druid,nishantmonu51/druid,mghosh4/druid,deltaprojects/druid,himanshug/druid