message: language-service: specify typescript as a peerDep
  don't install a specific version for users.
diff: "test:unit": "mocha test/lib/**/*.spec.ts test/lib/*.spec.ts",
  "prepack": "yarn build"
  },
  + "peerDependencies": {
  + "typescript": ">=3.6"
  + },
  "dependencies": {
  "@file-services/node": "^2.1.1",
  "@file-services/typescript": "^2.1.2",
  "css-selector-tokenizer": "^0.7.1",
  "postcss": "^7.0.27",
  "postcss-value-parser": "^4.0.3",
  - "typescript": "~3.8.2",
  "vscode-css-languageservice": "^4.0.2",
  "vscode-languageserver": "^6.1.1",
  "vscode-uri": "^2.1.1"
  