[New Chapter] CGP Patterns: Error Handling

[soareschen]

A few new chapters for CGP Patterns have been released, with a deep dive into error handling: https://patterns.contextgeneric.dev/error-handling.html

The introduction to error handling in CGP is very important, as it is very different from how error handling is typically done in Rust. The error handling techniques are also useful for showing how various CGP patterns, such as associated types, can be used to solve various programming patterns. So once the readers understood CGP error handling, they can also apply the same patterns in other problem domains.