`github>gander-settings/renovate`

The default preset, loaded when you reference the repo with no preset name. It is base plus automerge, and it is the usual choice for every repo.

{
  "$schema": "https://docs.renovatebot.com/renovate-schema.json",
  "extends": ["github>gander-settings/renovate"]
}

List it first in extends and add modifiers after it.

What you get

Everything in base: release age 3/5/7 days for patch/minor/major, pinned GitHub Actions digests, separate PRs per update type, monorepo grouping, semantic commits, no lock file maintenance, no dependency dashboard.
Everything in automerge: patches, GitHub Actions pins and digests, and vulnerability fixes merge themselves once CI is green; minor and major updates never do.