build(deps-dev): update typescript requirement from ^3.7.2 to ^3.8.3

Updates the requirements on [typescript](https://github.com/Microsoft/TypeScript) to permit the latest version.
- [Release notes](https://github.com/Microsoft/TypeScript/releases)
- [Commits](microsoft/TypeScript@v3.7.2...v3.8.3)

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

Author: dependabot-preview[bot]

package.json

@@ -30,7 +30,7 @@
     "rollup-plugin-terser": "^5.1.2",
     "ts-jest": "^24.3.0",
     "ts-node": "^8.8.2",
-    "typescript": "^3.7.2",
+    "typescript": "^3.8.3",
     "vuepress": "^1.4.0"
   },
   "scripts": {