chore(deps): bump commander from 4.1.1 to 6.1.0

Bumps [commander](https://github.com/tj/commander.js) from 4.1.1 to 6.1.0.
- [Release notes](https://github.com/tj/commander.js/releases)
- [Changelog](https://github.com/tj/commander.js/blob/master/CHANGELOG.md)
- [Commits](https://github.com/tj/commander.js/compare/v4.1.1...v6.1.0)

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

packages/docgen/package.json

@@ -27,7 +27,7 @@
   },
   "dependencies": {
     "chalk": "^4.0.0",
-    "commander": "^4.1.1",
+    "commander": "^6.1.0",
     "fs-extra": "^9.0.0",
     "github-slugger": "^1.3.0",
     "ts-node": "^8.6.2",