Danconnolly/rust-bitcoinsv

AI Summary: Improve the documentation of the rust-bitcoinsv library by adding comprehensive examples, detailed explanations of the `Encodable` trait and implementation choices, a usage guide, and enhanced API documentation with error, panic, and safety sections. This involves writing clear and concise documentation following Rust API guidelines and using doc tests to ensure accuracy.

AI Summary: Refactor the BitcoinSV library to remove all instances of `unwrap()` from production code, replacing them with proper error handling mechanisms such as `?`, `unwrap_or_default()`, or `expect()` with descriptive messages. This involves fixing critical instances in key functions, improving error handling in the public API, and adding tests to cover new error paths. The goal is to prevent panics in production and improve the robustness of the library.