chore: add diff view

Author: atlj

.github/workflows/comment-diffs.yml

@@ -211,7 +211,9 @@ jobs:
               # Add type to output file
               message="""<details>
               <summary>${library_type}/${language}</summary>"""
-              echo """${message}""" >> $output_file
+              echo """```diff
+              ${message}
+              ```""" >> $output_file
 
               # Add changes to output file
               git diff HEAD~ >> $output_file