rename devfile/kubernetes-api to devfile/api

[sbose78]

Describe the bug

Similar to openshift/api or kubernetes/api, it would be nice to have devfile/api.
The name kubernetes-api makes it look like Kubernetes API Server-ish API :)

[l0rd]

Yes I think we should do that indeed. Le's wait for @davidfestal +1 here as well and then let's rename it.

[davidfestal]

I'm OK with this as well.

[gorkem]

+1
Let's do this as soon as possible

[neeraj-laad]

+1
This would make it much clearer.

[l0rd]

Renamed

[amisevsk]

Follow up PR: #110