Final Alex Jar file

What's Changed

• add comments for stream feature by @yikyak02 in #3
• Add assertions to Alex and Storage classes for validation and error h… by @yikyak02 in #1
• Refactor Storage class to improve code quality and readability by @yikyak02 in #2

New Contributors

• @yikyak02 made their first contribution in #3

Full Changelog: https://github.com/yikyak02/ip/commits/v0.2