Bump lodash from 4.17.20 to 4.17.21

Bumps [lodash](https://github.com/lodash/lodash) from 4.17.20 to 4.17.21.
- [Release notes](https://github.com/lodash/lodash/releases)
- [Commits](lodash/lodash@4.17.20...4.17.21)

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

Author: dependabot[bot]

package-lock.json

@@ -64,7 +64,7 @@
     "js-yaml": "^3.14.0",
     "linkinator": "^2.13.6",
     "liquidjs": "^9.22.1",
-    "lodash": "^4.17.20",
+    "lodash": "^4.17.21",
     "lunr": "^2.3.9",
     "lunr-languages": "^1.4.0",
     "mdast-util-from-markdown": "^0.8.4",