Clean up comment sections and fix typos in CmdRun

Docker-DCO-1.1-Signed-off-by: Phil Estes <estesp@linux.vnet.ibm.com> (github: estesp)
Fixes #8690

Docker-DCO-1.1-Signed-off-by: Jessica Frazelle <jess@docker.com> (github: jfrazelle)
Merge pull request #8692 from jfrazelle/8690-latest-tag-problem

Fix problem where building Dockerfile `FROM name:latest`
Merge pull request #8672 from estesp/CmdRun-fix-typos-comments

Clean up comment sections and fix typos in CmdRun