Moves focus away from functions, Swarm and Docker Inc to reflect
some of the changes to the core project over the three years since
initial launch.

OpenFaaS can run any container that conforms to the runtime
contract. OpenFaaS Cloud provides IaaC and GitOps, but it was hard
to show where it belonged.

Some people are also under the impression that a container registry
is not required, so this diagram should clear that up.

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <alexellis2@gmail.com>