docs: removal of deprecated cache.appcache file

Author: Ubayed-Bin-Sufian

lib/README.md

@@ -41,3 +41,8 @@ If you need to view or modify the original source code, it's best to refer to th
 | 29  | `wheelnav.js`                         | [wheelnav](https://github.com/softwaretailoring/wheelnav)                                            |
 
 <!-- TODO: Add a separate column for description for libs -->
+
+## Deprecated Files Removed
+
+- The deprecated `cache.appcache` file has been removed from the codebase.
+  - **Reason**: We have already migrated to the modern **Service Worker** approach for handling offline functionality and caching, making `cache.appcache` obsolete and unnecessary.