[Docs] Add back documentation of post-run hook retry behavior
[Docs] Add back documentation of post-run hook retry behavior

This also went missing in #6925, but I missed it in my previous fixup
in #6979.

Signed-off-by: Christopher Maier <b4598f17a90ef80817bae8ad6c37249740caafb4@chef.io>

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