Suggestion: use word "server" instead of word "API" in docs
Hello.

When I first used this module I couldn't find server side example implementation until @jaydenseric pointed me to it. Thanks!

The problem was and still is - the wording. The common way is "client + server", but in the modern multi-cloud worlds the people use "backend + frontend".

Whereas, the API stand for Application Programming Interface ([definition](https://www.google.com/search?q=define%3Aapi)). For example, every NPM module have an API. Operating systems have API. OS kernels have API. Every class/interface (as in OOP) have an API. Databases have API. Even the `graphql-upload` itself have own API.

Currently, in the README, the word API used interchangeable for the module API - https://github.com/jaydenseric/graphql-upload#api , and for the server side code - https://github.com/jaydenseric/graphql-upload#usage

I would like to supply a PR fixing that word misuse in the following repos:
* https://github.com/jaydenseric/graphql-upload
* https://github.com/jaydenseric/apollo-upload-client
* https://github.com/jaydenseric/apollo-upload-examples
* else?

How does that sound?