Fixes a couple small typos

Docker-DCO-1.1-Signed-off-by: Fred Lifton <fred.lifton@docker.com> (github: fredlf)
Merge branch 'adding_official-repo-guidelines' of https://github.com/fredlf/docker into adding_official-repo-guidelines

Conflicts:
	docs/sources/docker-hub/official_repos.md

Docker-DCO-1.1-Signed-off-by: Fred Lifton <fred.lifton@docker.com> (github: fredlf)