Add New Section: Reading and Writing JSON and YAML

[davorg]

Introduce JSON::MaybeXS and YAML::XS (or YAML::PP) as modern, recommended tools for parsing and emitting structured data. Include examples for config loading, API responses, and munging structured input/output.

[briandfoy]

Also, Cpanel::JSON::XS.

There's a tricky thing to consider here, too. YAML is a big mess with multiple versions, and the modules don't always play nicely with each other. It's a continuing hassle with some stuff I do. See https://github.com/briandfoy/yaml-module-test .