message: build(tsc): improve TypeScript config
  target `es2018` since we're Node v14 and up
  don't bother excluding `node_modules` as it is already excluded
  don't set `typeRoots` manually, `tsc` knows what to do
diff: {
  "compilerOptions": {
  "strict": true,
  - "target": "es5",
  + "target": "es2018",
  "module": "commonjs",
  - "typeRoots": ["node_modules/@types"],
  "declaration": true,
  "lib": ["es2015"],
  "experimentalDecorators": true,
  "resolveJsonModule": true,
  "esModuleInterop": true
  },
  - "exclude": ["node_modules", "dist/**/*"]
  + "exclude": ["dist"]
  }
  