message: remove unused dependencies from package.json
diff: "dependencies": {
  "@backstage/core-components": "^0.7.6",
  "@backstage/core-plugin-api": "^0.2.2",
  - "@backstage/theme": "^0.2.14",
  - "@changesets/cli": "^2.14.0",
  "@material-ui/core": "^4.12.2",
  "@material-ui/icons": "^4.9.1",
  "@material-ui/lab": "4.0.0-alpha.57",
  - "@microsoft/api-documenter": "^7.13.68",
  - "@microsoft/api-extractor": "^7.18.7",
  - "@microsoft/api-extractor-model": "^7.13.5",
  - "concurrently": "^6.0.0",
  "cross-fetch": "^3.0.6",
  - "lint-staged": "^11.1.2",
  - "prettier": "^2.2.1",
  "qs": "^6.10.1",
  "react": "^16.13.1",
  - "react-dom": "^16.13.1",
  "react-use": "^17.2.4"
  },
  "devDependencies": {
  