Added information about username & password authentication

[Kodarru]

Extending: #2

[Kodarru]

If you want me to, I can write up add the authentication in https://github.com/Daniel-Boll/charydbis.js/blob/main/examples/basic/index.ts

[Daniel-Boll]

Hey @Kodarru! I appreciate your intent, I have just introduced the concept of the documentations folder, perhaps you can add a auth.md there.

About the example, the idea is to it to be simple and to be fair it already is using more concepts like clustering and partition keys that aren't needed in a basic example, I will also create a issue to split into more examples, so we won't need that for now.