Note on Wayback Machine added to readme

README.md

@@ -1,6 +1,6 @@
 # Internet Archive Downloader
 
-This Python script uses multithreading and multiprocessing in conjunction with the [Internet Archive Python Library](https://archive.org/services/docs/api/internetarchive/) to provide bulk downloads of files associated with Internet Archive ([archive.org](https://archive.org/)) items, with optional interrupted download resumption and file hash verification.
+This Python script uses multithreading and multiprocessing in conjunction with the [Internet Archive Python Library](https://archive.org/services/docs/api/internetarchive/) to provide bulk downloads of files associated with Internet Archive ([archive.org](https://archive.org/)) items and collections, with optional interrupted download resumption and file hash verification. Wayback Machine ([web.archive.org](https://web.archive.org/)) pages are not supported by this script.
 
 ## Getting started