Document OSI Model and its layers

Update README with new section on Cyber Security 101

Update progress percentage in README

Document cryptography concepts and insights

Document CIA Triad principles and personal insights

Update README with Pre Security Path progress

Revise module completion percentages in README

Update course topics in README

Update section title and add completed modules

Enhance Data Encoding Writeup with detailed concepts

Revise README with new title and content

Initial commit