Remove some docs in favor of moving them directly to the product docs

[myarmolinsky]

Change-type: patch

Connects-to: balena-io/docs#3476
Connects-to: balena-io/docs#3489
Fibery: https://balena.fibery.io/Work/Project/Move-non-reference-external-docs-directly-into-the-docs-2487
Fibery: https://balena.fibery.io/Work/Improvement/Review-all-automations-with-a-focus-on-reducing-their-number-3933
Fibery: https://balena.fibery.io/Work/Improvement/balena-os-meta-balena-4222

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Contributor checklist

• Changes have been tested
  • Covered in automated test suite
  • Manual test case recorded
• Change-type present on at least one commit
• Signed-off-by is present
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[flowzone-app]

Website deployed to CF Pages, 👀 preview link https://44e90093.balena-os.pages.dev

[alexgg]

lgtm

[myarmolinsky]

/rebase