[docs/getting_started] Fix kubectl apply command

[davidor]

What does this PR do?

Fixes a kubectl apply command in the getting started docs.

[codecov-commenter]

Codecov Report

Merging #356 (55eb113) into main (7cb27ba) will increase coverage by 25.77%.
The diff coverage is n/a.

@@             Coverage Diff             @@
##             main     #356       +/-   ##
===========================================
+ Coverage   38.95%   64.72%   +25.77%     
===========================================
  Files          65       63        -2     
  Lines       11462     6898     -4564     
===========================================
  Hits         4465     4465               
+ Misses       6678     2114     -4564     
  Partials      319      319               

Flag	Coverage Δ
unittests	64.72% <ø> (+25.77%)	⬆️

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Impacted Files	Coverage Δ
api/v1alpha1/zz_generated.deepcopy.go
api/v1alpha1/zz_generated.openapi.go

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