🤖 Auto-sync docs, metadata, and filepaths (#3127)

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

Author: github-actions[bot]

exercises/practice/grep/.docs/introduction.md

@@ -0,0 +1,5 @@
+# Introduction
+
+You have taken a job at a local library helping organize their collection of old books.
+The student patrons are often hunting for half-remembered quotes to cite in their term papers.
+Rather than manually read every book from cover to cover, you decide to build a small tool to scan them, looking for these partial quotes.

exercises/practice/prism/.meta/config.json

@@ -11,6 +11,9 @@
     ],
     "example": [
       ".meta/src/reference/java/Prism.java"
+    ],
+    "invalidator": [
+      "build.gradle"
     ]
   },
   "blurb": "Calculate the path of a laser through refractive prisms.",