documentation 📄

add documentation of entire application.
- methods should have parameter documentation
- swift closures should be closing brace indictor
- extensions should have examples
- models should have every variable documented

references:
https://sarunw.com/posts/swift-documentation/

The issue asks for comprehensive documentation across the entire iOS application. Start by exploring the repository structure to identify key files, especially models, methods, extensions, and closures. Use the provided Swift documentation guide as a reference. Check existing code for patterns and add documentation following the examples. Ensure each variable, parameter, and closure is documented, and extensions include usage examples.

Written by the indexing model from the issue text.