Improve formatting of configuration.md
Improve formatting of configuration.md

Signed-off-by: Misty Stanley-Jones <b9f9ef9e00c258208ea831c64cc129eda4ac78b4@docker.com>

harrisonfeng/distribution,jwhonce/distribution,mikebrow/distribution,yuwaMSFT2/distribution,konstruktoid/distribution,konnase/distribution,konstruktoid/distribution,docker/distribution,vdemeester/distribution,miminar/distribution,jwhonce/distribution,sergeyfd/distribution,thaJeztah/distribution,vdemeester/distribution,mikebrow/distribution,dmcgowan/distribution,miminar/distribution,estesp/distribution,thaJeztah/distribution,duglin/distribution,yuwaMSFT2/distribution,huamai-io/distribution,shyr/distribution,huamai-io/distribution,sergeyfd/distribution,harrisonfeng/distribution,dmcgowan/distribution,spacexnice/distribution,spacexnice/distribution,jzwlqx/distribution,manoj535/distribution,konnase/distribution,jzwlqx/distribution,sadlil/distribution,manoj535/distribution,cezarsa/distribution,estesp/distribution,sadlil/distribution,duglin/distribution,shyr/distribution,docker/distribution,cezarsa/distribution