build(deps-dev): bump tsd from 0.19.1 to 0.20.0

Bumps [tsd](https://github.com/SamVerschueren/tsd) from 0.19.1 to 0.20.0.
- [Release notes](https://github.com/SamVerschueren/tsd/releases)
- [Commits](tsdjs/tsd@v0.19.1...v0.20.0)

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

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

package.json

@@ -30,7 +30,7 @@
     "proxyquire": "^2.1.3",
     "standard": "^16.0.3",
     "tap": "^16.0.1",
-    "tsd": "^0.19.0",
+    "tsd": "^0.20.0",
     "typescript": "^4.0.5"
   },
   "dependencies": {}