Update prettier to v2.4.0

| datasource | package  | from  | to    |
| ---------- | -------- | ----- | ----- |
| npm        | prettier | 2.3.2 | 2.4.0 |

Author: renovate-bot

package-lock.json

@@ -28,7 +28,7 @@
     "eslint-config-prettier": "^8.3.0",
     "eslint-rule-documentation": "1.0.23",
     "jest": "27.1.1",
-    "prettier": "2.3.2"
+    "prettier": "2.4.0"
   },
   "peerDependencies": {
     "eslint": "^7.2.0",