chore(deps-dev): bump memdown from 4.1.0 to 5.1.0

Bumps [memdown](https://github.com/Level/memdown) from 4.1.0 to 5.1.0.
- [Release notes](https://github.com/Level/memdown/releases)
- [Changelog](https://github.com/Level/memdown/blob/master/CHANGELOG.md)
- [Commits](Level/memdown@v4.1.0...v5.1.0)

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

package.json

@@ -48,7 +48,7 @@
     "cids": "~0.8.0",
     "detect-node": "^2.0.4",
     "dirty-chai": "^2.0.1",
-    "memdown": "^4.0.0",
+    "memdown": "^5.1.0",
     "rimraf": "^2.6.2"
   },
   "contributors": [