/kind feature

What happened:
The docs for http liveness probes only reference httpGet, but a http HEAD request is better for healthchecks as no data is returned so it is lighter weight.

What you expected to happen:
I would expect a httpHead directive to exist. It would perform a request such as:

HEAD / HTTP/1.1

vs httpGet, which does something like:

GET / HTTP/1.1

How to reproduce it (as minimally and precisely as possible):

Create a livenessProbe and be 😞 that HEAD requests aren't available.