build(deps): bump slate from 0.58.3 to 0.59.0 (#36)

Bumps [slate](https://github.com/ianstormtaylor/slate) from 0.58.3 to 0.59.0.
- [Release notes](https://github.com/ianstormtaylor/slate/releases)
- [Changelog](https://github.com/ianstormtaylor/slate/blob/master/Changelog.md)
- [Commits](https://github.com/ianstormtaylor/slate/compare/v0.58.3...v0.59.0)

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

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>

packages/example/package.json

@@ -24,7 +24,7 @@
     "react": "^16.9.0",
     "react-dom": "^16.9.0",
     "react-scripts": "3.1.2",
-    "slate": "0.58.3",
+    "slate": "0.59.0",
     "slate-history": "0.58.3",
     "slate-react": "0.58.3",
     "typescript": "^3.8.3"