kubernetes: Simplify and freshen the required-files table
kubernetes: Simplify and freshen the required-files table

The cri-o entries are stale vs. the content currently installed by the
Makefile.  This commit drops them and just references the make call
before starting the table, which lets us stay DRY.

runc is not built from the cri-o repository.  The docs have claimed it
was since 983aec63 (doc: Add instruction to run cri-o with kubernetes,
2017-01-31, #353), but it's independent like the CNI plugins.

The CNI plugins were moved to containernetworking/plugins in
containernetworking/cni@bc0d09e (plugins: moved to
containernetworking/plugins, 2017-05-17, containernetworking/cni#457).

I've added a link to the in-repo policy.json example.  We probably
also want to link to the docs (for the version we vendor?) [1], but
I've left that alone for now.

The CNI config examples were removed from the project README in
9088a12c (contrib: cni: provide example CNI configurations,
2016-12-24, #295).  I've adjusted the reference to point to the new
location, although again, I'd rather replace this with links to
upstream docs.

[1]: https://github.com/containers/image/blob/3d0304a02154dddc8f97cc833aa0861cea5e9ade/docs/policy.json.md

Signed-off-by: W. Trevor King <f75897670c17327c42ab201733fb8a81ff9f4c34@tremily.us>

kubernetes-incubator/ocid,mikebrow/cri-o,mikebrow/cri-o,kubernetes-incubator/cri-o,rhatdan/cri-o,14rcole/cri-o,mikebrow/cri-o,rhatdan/cri-o,vbatts/cri-o,kubernetes-incubator/ocid,kubernetes-incubator/cri-o,kubernetes-incubator/cri-o,14rcole/cri-o,vbatts/cri-o,mikebrow/cri-o,nalind/cri-o,nalind/cri-o,14rcole/cri-o,jwhonce/ocid,vbatts/cri-o,jwhonce/ocid,vbatts/cri-o,nalind/cri-o,kubernetes-incubator/ocid,rhatdan/cri-o,kubernetes-incubator/cri-o,14rcole/cri-o,rhatdan/cri-o,jwhonce/ocid