Move prettier to peerDependencies (#529)

Author: fvictorio

package-lock.json

@@ -74,15 +74,18 @@
     "jest-watch-typeahead": "^0.6.4",
     "lines-and-columns": "^1.1.6",
     "outdent": "^0.8.0",
+    "prettier": "^2.3.1",
     "solc": "^0.8.4"
   },
   "dependencies": {
     "@solidity-parser/parser": "^0.13.2",
     "emoji-regex": "^9.2.2",
     "escape-string-regexp": "^4.0.0",
-    "prettier": "^2.3.1",
     "semver": "^7.3.5",
     "solidity-comments-extractor": "^0.0.7",
     "string-width": "^4.2.2"
+  },
+  "peerDependencies": {
+    "prettier": "^2.3.1"
   }
 }