build(deps): bump gatsby-plugin-react-helmet in /docs

Bumps [gatsby-plugin-react-helmet](https://github.com/gatsbyjs/gatsby/tree/HEAD/packages/gatsby-plugin-react-helmet) from 5.13.0 to 5.17.0.
- [Release notes](https://github.com/gatsbyjs/gatsby/releases)
- [Changelog](https://github.com/gatsbyjs/gatsby/blob/master/packages/gatsby-plugin-react-helmet/CHANGELOG.md)
- [Commits](https://github.com/gatsbyjs/gatsby/commits/gatsby-plugin-react-helmet@5.17.0/packages/gatsby-plugin-react-helmet)

---
updated-dependencies:
- dependency-name: gatsby-plugin-react-helmet
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

docs/package-lock.json

@@ -21,7 +21,7 @@
     "gatsby-plugin-netlify": "^4.3.1",
     "gatsby-plugin-netlify-cache": "^2.0.0",
     "gatsby-plugin-offline": "^5.13.0",
-    "gatsby-plugin-react-helmet": "^5.13.0",
+    "gatsby-plugin-react-helmet": "^5.17.0",
     "gatsby-plugin-react-svg": "^3.1.0",
     "gatsby-plugin-robots-txt": "^1.7.1",
     "gatsby-plugin-sharp": "^4.13.0",