serpapi/serpapi-javascript ? reverse-engineered prompt

Build me a small TypeScript library for JavaScript and Deno that makes it easy to use SerpApi to fetch search results from engines like Google, Bing, and the others they support.

I want one simple package that works in Node and Deno, lets me call things like getJson and getHtml, and supports both async await and old style callbacks. It should let me set a global API key and timeout, but also override them per request when needed. Please include the helper methods for getting results by search ID, account info, and locations too.

Make sure the examples are easy to follow, and include basic usage for CommonJS, ESM, and Deno. If there are any current SerpApi or runtime docs that would help, look them up online and follow the latest guidance.