Bump typescript from 3.5.3 to 3.6.4

Bumps [typescript](https://github.com/Microsoft/TypeScript) from 3.5.3 to 3.6.4.
- [Release notes](https://github.com/Microsoft/TypeScript/releases)
- [Commits](microsoft/TypeScript@v3.5.3...v3.6.4)

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

package.json

@@ -74,7 +74,7 @@
     "tslint-config-prettier": "^1.18.0",
     "tslint-plugin-prettier": "^2.0.1",
     "tslint-xo": "^0.16.0",
-    "typescript": "^3.5.3"
+    "typescript": "^3.6.4"
   },
   "keywords": [
     "gatsby"