Added husky/lint-staged to run prettier on precommit

Doc: https://prettier.io/docs/en/precommit.html

Author: trivikr

Diff for: package.json

@@ -43,6 +43,20 @@
     "@types/react-dom": "^16.8.2",
     "@typescript-eslint/eslint-plugin": "^1.5.0",
     "@typescript-eslint/parser": "^1.5.0",
+    "husky": "^1.3.1",
+    "lint-staged": "^8.1.5",
+    "prettier": "1.16.4",
     "typescript": "~3.3.4000"
+  },
+  "husky": {
+    "hooks": {
+      "pre-commit": "lint-staged"
+    }
+  },
+  "lint-staged": {
+    "*.{js,json,ts,tsx,css,md}": [
+      "prettier --write",
+      "git add"
+    ]
   }
 }