pkg-export-k8s: Make some help strings consistent
pkg-export-k8s: Make some help strings consistent

Should start with uppercase, just like others.

Signed-off-by: Krzesimir Nowak <049588669667d6bb20b978e17fc57ff3556ea5dd@kinvolk.io>

habitat-sh/habitat,rsertelon/habitat,habitat-sh/habitat,rsertelon/habitat,rsertelon/habitat,habitat-sh/habitat,habitat-sh/habitat,rsertelon/habitat,habitat-sh/habitat,rsertelon/habitat,rsertelon/habitat,habitat-sh/habitat,habitat-sh/habitat,habitat-sh/habitat,rsertelon/habitat