Exposing Types for TypeScript

Typings for Nano are not exposed or able to import through TypeScript

## Expected Behavior
being able to define types and add Nano.ServerScope as a typings to my objects and functions
`const NanoInstances = new Map();`

## Current Behavior
instead, we have to create a dummy instance to localhost and extract the reference as follows
```ts
const nanoInstance = Nano('http://localhost:5894');
type NanoType = typeof nanoInstance;

// Now you can use NanoType to reference the typings
const NanoServers = new Map();

function findDoc (instance: NanoType, doc: string){
//...
}
```

## Possible Solution
just need to expose the types through an entry point or export them directly

## Context
I am building a modular platform that allows multiple Nano instances to be present and are configured dynamically.
since we are using strict type safety, its better to use the correct typing's vs `any` or `unknown`

## Your Environment
* Version used: "nano": "^10.1.3",
* Browser Name and version: node v18.17.0

No file or test is named in the issue. Start by locating the package's existing TypeScript declarations and public export entry point, then verify that ServerScope can be imported without creating a Nano instance; add or update focused type/export coverage if the repository has it.

Written by the indexing model from the issue text.