Bump gatsby-transformer-remark from 3.0.0 to 3.1.0 (#97)

Bumps [gatsby-transformer-remark](https://github.com/gatsbyjs/gatsby/tree/HEAD/packages/gatsby-transformer-remark) from 3.0.0 to 3.1.0.
- [Release notes](https://github.com/gatsbyjs/gatsby/releases)
- [Changelog](https://github.com/gatsbyjs/gatsby/blob/master/packages/gatsby-transformer-remark/CHANGELOG.md)
- [Commits](https://github.com/gatsbyjs/gatsby/commits/gatsby-transformer-remark@3.1.0/packages/gatsby-transformer-remark)

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Johannes Konings <johannes.konings@outlook.com>

package.json

@@ -21,7 +21,7 @@
     "gatsby-plugin-react-helmet": "4.1.0",
     "gatsby-plugin-sass": "4.0.2",
     "gatsby-source-filesystem": "3.1.0",
-    "gatsby-transformer-remark": "3.0.0",
+    "gatsby-transformer-remark": "3.1.0",
     "js-yaml": "^4.0.0",
     "lodash": "^4.17.21",
     "marked": "^2.0.1",