Use third-person verb forms in command help

[dmerand]

WHY are these changes introduced?

Command help mixes imperative wording with third-person descriptions. Use the same verb form in summaries and opening descriptions, as if each follows “This command…”.

WHAT is this pull request doing?

Change imperative verbs to third-person singular in in-tree command help. Keep the meaning and remaining wording unchanged, including later sentences. Regenerate the command manifests and README.

How to manually test your changes?

Run pnpm shopify app config link --help, pnpm shopify app bulk status --help, and pnpm shopify config autocorrect on --help. Check that the summary and opening description use third-person verbs, and that the remaining help text is unchanged.

Checklist

• I've considered possible cross-platform impacts (Mac, Linux, Windows)
• I've considered possible documentation changes
• I've considered analytics changes to measure impact
• The change is user-facing — I've identified the correct bump type (patch for bug fixes · minor for new features · major for breaking changes) and added a patch changeset