Add workaround for DTR installation when using --external-url parameter (#9485)
Add workaround for DTR installation when using --external-url parameter (#9485)

* Added info about load balancer to Step 3: Install
DTR; various formatting changes to the page.

Signed-off-by: Lena Larionova <88a29fa60f025c67f8178c0937d78d6fde38c940@docker.com>

* formatting

Signed-off-by: Lena Larionova <88a29fa60f025c67f8178c0937d78d6fde38c940@docker.com>

docker/docker.github.io,thaJeztah/docker.github.io,thaJeztah/docker.github.io,docker/docker.github.io,docker/docker.github.io,thaJeztah/docker.github.io,thaJeztah/docker.github.io,docker/docker.github.io,thaJeztah/docker.github.io,docker/docker.github.io