mindwingx/gocally ? reverse-engineered prompt

Build me a small Go library for making HTTP and API calls that feels really simple and chainable. I want to be able to start with something like SetRequest(), add a URL, headers, auth, query params, a JSON body or multipart form values, change the timeout, and then call Get, Post, Put, or Delete. Please make JSON accept and content type headers enabled by default, with an option to turn them off.

The response side should be easy too. I want one method that returns the raw HTTP response, one that gives me status, status code, and a decoded payload as a generic map, and one that can decode into a struct I pass in. Keep it minimal and fast, with sensible defaults like a 10 second timeout. Please include solid tests and a short README with copy and paste examples that show the full flow from request setup to reading the response. If you need to, look up current Go docs online.