Fix indent in package.json example (#2843)

Author: SyntaxCacao

src/content/guides/getting-started.md

@@ -98,8 +98,8 @@ __package.json__
     "author": "",
     "license": "ISC",
     "devDependencies": {
-    "webpack": "^4.20.2",
-    "webpack-cli": "^3.1.2"
+      "webpack": "^4.20.2",
+      "webpack-cli": "^3.1.2"
     },
     "dependencies": {}
   }