Previously, the ytt install docs suggested that you use ytt templates
from the HEAD of main with the container image from the latest public
release, which could result in a mismatch.
The documentation was a bit confusing before, and it was easy to accidentally install a very outdated version if you weren't reading carefully.
We could consider writing a post-release CI job to update these references automatically (perhaps using a Hugo macro?), but for now a manual update seems sufficient.
Signed-off-by: Matt Moyer <moyerm@vmware.com>
