🤖 Auto-sync docs, metadata, and filepaths (#375)

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

Author: github-actions[bot]

exercises/practice/perfect-numbers/.meta/config.json

@@ -18,5 +18,5 @@
   },
   "blurb": "Determine if a number is perfect, abundant, or deficient based on Nicomachus' (60 - 120 CE) classification scheme for positive integers.",
   "source": "Taken from Chapter 2 of Functional Thinking by Neal Ford.",
-  "source_url": "https://www.oreilly.com/library/view/functional-thinking/9781449365509/"
+  "source_url": "https://nealford.com/books/functionalthinking.html"
 }