Re-add PostCSS as a regular dependency

package.json

@@ -40,6 +40,7 @@
     "insert-css": "^2.0.0",
     "map-obj": "^4.1.0",
     "object.fromentries": "^2.0.1",
+    "postcss": "^8.4.12",
     "postcss-modules-extract-imports": "^3.0.0",
     "postcss-modules-local-by-default": "^4.0.0",
     "postcss-modules-scope": "^3.0.0",
@@ -48,7 +49,6 @@
   },
   "devDependencies": {
     "@joepie91/eslint-config": "^1.1.0",
-    "eslint": "^6.8.0",
+    "eslint": "^6.8.0"
-    "postcss": "^8.0.0"
   }
 }