Added health check docs, & details on updating apps (#11729)
Added health check docs, & details on updating apps (#11729)

* Added health check docs, & details on updating apps

Signed-off-by: Guillaume Tardif <fdb6d90518c0d82cc6b9e4626ba807cce7a41bc7@docker.com>

* Apply suggestions from code review

Co-authored-by: Chris Crone <0bd24f27efbdecb22ed8ee46cb16be12b5608d69@docker.com>
Co-authored-by: Usha Mandya <63fc8324d194bb900191b7ad7215ea10fd135fb2@users.noreply.github.com>

* Minor format updates

Fixed typos, removed extra blank lines

Co-authored-by: Chris Crone <0bd24f27efbdecb22ed8ee46cb16be12b5608d69@docker.com>
Co-authored-by: Usha Mandya <63fc8324d194bb900191b7ad7215ea10fd135fb2@users.noreply.github.com>
docker/docker.github.io,thaJeztah/docker.github.io,docker/docker.github.io,docker/docker.github.io,thaJeztah/docker.github.io,docker/docker.github.io,thaJeztah/docker.github.io,thaJeztah/docker.github.io,thaJeztah/docker.github.io,docker/docker.github.io