build(deps-dev): bump tsd from 0.20.0 to 0.21.0 (#313)

Bumps [tsd](https://github.com/SamVerschueren/tsd) from 0.20.0 to 0.21.0.
- [Release notes](https://github.com/SamVerschueren/tsd/releases)
- [Commits](tsdjs/tsd@v0.20.0...v0.21.0)

---
updated-dependencies:
- dependency-name: tsd
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

package.json

@@ -53,7 +53,7 @@
     "snazzy": "^9.0.0",
     "standard": "^17.0.0",
     "tap": "^16.0.0",
-    "tsd": "^0.20.0",
+    "tsd": "^0.21.0",
     "typescript": "^4.0.2"
   },
   "tsd": {