Hygiene: enabled presets properly.

[bendory]

Changes

This change looks like it's whitespace only, but in fact it enables the presets in the config!

Prior to this change, the top-level presets: field was ignored. This change properly indents presets:
so that it's a field in the linters: block -- thereby enabling the presets.

Also: added comments documenting the enabled issues.include items.

There are no functional changes in this PR.

Context: tektoncd/pipeline#5899

/kind misc

Submitter Checklist

As the author of this PR, please check off the items in this checklist:

• [N/A] Has Docs included if any changes are user facing
• Has Tests included if any functionality added or changed
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• Meets the Tekton contributor standards (including
  functionality, content, code)
• Release notes block below has been updated with any user facing changes (API changes, bug fixes, changes requiring upgrade notices or deprecation warnings)
• [N/A] Release notes contains the string "action required" if the change requires additional action from users switching to the new release

Release Notes

NONE

[lcarva]

/lgtm

[tekton-robot]

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