Add graphql-api-koa to the GraphQL servers list

[jaydenseric]

graphql-api-koa is a GraphQL.js implementation written from scratch for Koa. It is the only such alternative to apollo-server-koa as koa-graphql just wraps express-graphql.

Uniquely, it's separate errorHandler() and execute() middlewares allow Koa "onion" style error handling; middleware errors result in an appropriate GraphQL response with errors.

With a 96.5kb install size and a 3.2kb min+gzip bundle size, it is to my knowledge the lightest Node.js GraphQL server available. For comparison, apollo-server-koa has an 11.8M install size and koa-graphql has a 3.03M install size.

The cherry on top is that it is the only GraphQL server to support native ESM for Node.js in --experimental-modules mode.

I've been using it in production for several APIs.