build(deps-dev): bump @nuxt/devtools from 1.2.0 to 1.3.1 in /docs

Bumps [@nuxt/devtools](https://github.com/nuxt/devtools/tree/HEAD/packages/devtools) from 1.2.0 to 1.3.1.
- [Release notes](https://github.com/nuxt/devtools/releases)
- [Changelog](https://github.com/nuxt/devtools/blob/main/CHANGELOG.md)
- [Commits](https://github.com/nuxt/devtools/commits/v1.3.1/packages/devtools)

---
updated-dependencies:
- dependency-name: "@nuxt/devtools"
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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