Add doc for missing balancerComputeThreads configuration (#6561)
Add doc for missing balancerComputeThreads configuration (#6561)

* Add doc for missing balancerComputeThreads configuration

* remove duplicate

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