chore(deps): update dependency typescript to v4 (#123)

Co-authored-by: Renovate Bot <bot@renovateapp.com>

Author: renovate[bot]

package.json

@@ -59,7 +59,7 @@
     "rimraf": "^3.0.0",
     "shipjs": "^0.20.0",
     "ts-node": "^8.10.2",
-    "typescript": "^3.9.7",
+    "typescript": "^4.0.0",
     "vue-github-button": "^1.2.0",
     "vuepress": "^1.5.2"
   },

yarn.lock

@@ -10275,10 +10275,10 @@ typedarray@^0.0.6:
   resolved "https://registry.yarnpkg.com/typedarray/-/typedarray-0.0.6.tgz#867ac74e3864187b1d3d47d996a78ec5c8830777"
   integrity sha1-hnrHTjhkGHsdPUfZlqeOxciDB3c=
 
-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@^4.0.0:
+  version "4.0.2"
+  resolved "https://registry.yarnpkg.com/typescript/-/typescript-4.0.2.tgz#7ea7c88777c723c681e33bf7988be5d008d05ac2"
+  integrity sha512-e4ERvRV2wb+rRZ/IQeb3jm2VxBsirQLpQhdxplZ2MEzGvDkkMmPglecnNDfSUBivMjP93vRbngYYDQqQ/78bcQ==
 
 uc.micro@^1.0.1, uc.micro@^1.0.5:
   version "1.0.6"