Upgrade TypeScript from v3.9.7 to v4.2.3
diff --git a/package.json b/package.json
index 4031f71..a1cf30c 100644
--- a/package.json
+++ b/package.json
@@ -77,7 +77,7 @@
     "resolve": "^1.15.0",
     "rimraf": "^3.0.0",
     "typedoc": "^0.20.5",
-    "typescript": "^3.9.7",
+    "typescript": "^4.2.3",
     "web-annotation-tests": "https://github.com/w3c/web-annotation-tests",
     "webpack": "^4.41.5",
     "webpack-cli": "^3.3.10",
diff --git a/yarn.lock b/yarn.lock
index 3dab07c..9984366 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -10186,10 +10186,10 @@
     shiki "^0.9.3"
     typedoc-default-themes "^0.12.9"
 
-typescript@^3.9.7:
-  version "3.9.7"
-  resolved "https://registry.yarnpkg.com/typescript/-/typescript-3.9.7.tgz#98d600a5ebdc38f40cb277522f12dc800e9e25fa"
-  integrity sha512-BLbiRkiBzAwsjut4x/dsibSTB6yWpwT5qWmC2OfuCg3GgVQCSgMs4vEctYPhsaGtd0AeuuHMkjZ2h2WG8MSzRw==
+typescript@^4.2.3:
+  version "4.2.3"
+  resolved "https://registry.yarnpkg.com/typescript/-/typescript-4.2.3.tgz#39062d8019912d43726298f09493d598048c1ce3"
+  integrity sha512-qOcYwxaByStAWrBf4x0fibwZvMRG+r4cQoTjbPtUlrWjBHbmCAww1i448U0GJ+3cNNEtebDteo/cHOR3xJ4wEw==
 
 uglify-js@^3.1.4:
   version "3.6.0"