docs: add detailed information on how to use helm rendering with v2.X.Y as well as how post-renderer usage works

[aaron-prindle]

fixes #8057

[codecov]

Codecov Report

Merging #8093 (72ed50c) into main (290280e) will decrease coverage by 3.99%.
The diff coverage is 53.61%.

❗ Current head 72ed50c differs from pull request most recent head 9bef416. Consider uploading reports for the commit 9bef416 to get more accurate results

@@            Coverage Diff             @@
##             main    #8093      +/-   ##
==========================================
- Coverage   70.48%   66.49%   -4.00%     
==========================================
  Files         515      597      +82     
  Lines       23150    29174    +6024     
==========================================
+ Hits        16317    19398    +3081     
- Misses       5776     8337    +2561     
- Partials     1057     1439     +382     

Impacted Files	Coverage Δ
cmd/skaffold/app/cmd/credits/export.go	0.00% <0.00%> (ø)
cmd/skaffold/app/cmd/deploy.go	40.90% <0.00%> (-12.94%)	⬇️
cmd/skaffold/app/cmd/test.go	44.44% <0.00%> (ø)
cmd/skaffold/app/exitcode.go	100.00% <ø> (+6.66%)	⬆️
cmd/skaffold/skaffold.go	0.00% <0.00%> (ø)
cmd/skaffold/app/cmd/inspect_tests.go	62.50% <14.28%> (-1.14%)	⬇️
cmd/skaffold/app/cmd/render.go	35.48% <18.18%> (-5.90%)	⬇️
cmd/skaffold/app/cmd/lsp.go	28.12% <28.12%> (ø)
cmd/skaffold/app/cmd/run.go	64.28% <33.33%> (-9.63%)	⬇️
cmd/skaffold/app/cmd/fix.go	56.41% <37.50%> (-20.07%)	⬇️
... and 394 more

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[container-tools-bot]

Error creating deployment docs-controller-deployment-8093, please visit https://storage.googleapis.com/webhook-logs/logs-8093-1668483664690554135 to view logs.

[gsquared94]

lgtm

[chris13524]

How to specify for multiple images?

[aaron-prindle]

Thanks for this feedback, I have made each example here have multiple images to make this clearer for users. Below is a snippet for the specific yaml you highlighted used with multiple images

values.yaml

image:
  registry: gcr.io
  repository: other-project/other-image
  tag: latest
image2:
  registry: gcr.io
  repository: other-project/other-image
  tag: latest

skaffold.yaml

build:
  artifacts:
    - image: my-image # must match in setValues
    - image: my-image-2 # must match in setValues
deploy:
  helm:
    releases:
      - name: my-chart
        chartPath: helm
        setValues:
          image.registry: my-image
          image.repository: my-image
          image.tag: my-image
          image2.registry: my-image-2
          image2.repository: my-image-2
          image2.tag: my-image-2