doc/tutorial/kubernetes: fix typo
doc/tutorial/kubernetes: fix typo

Change-Id: I8039c90369a160341cce93381dcd7277cd26a062
Reviewed-on: https://cue-review.googlesource.com/c/cue/+/2520
Reviewed-by: Marcel van Lohuizen <a22d082192f3ccf984644a4f482781f4c2d65180@google.com>

cuelang/cue