fix: upgrade prettier from 2.8.4 to 2.8.8

Snyk has created this PR to upgrade prettier from 2.8.4 to 2.8.8.

See this package in npm:
https://www.npmjs.com/package/prettier

See this project in Snyk:
https://app.snyk.io/org/mmomtchev/project/a61b11f8-08f4-4dba-abd2-aee35d09b3cc?utm_source=github&utm_medium=referral&page=upgrade-pr

package.json

@@ -132,7 +132,7 @@
     "null-loader": "^4.0.1",
     "ol": "^7.4.0",
     "ol-mbtiles": "^2.0.2",
-    "prettier": "2.8.4",
+    "prettier": "2.8.8",
     "prism-themes": "^1.6.0",
     "prismjs": "^1.28.0",
     "proj4": "^2.7.0",