feat: allow named export usage

The main exports of the package are now available both as named exports
from the package as well as the previously available properties from
the default export. This removes the requirement to use the `esModuleInterop`
TypeScript option but retains backward compatiblity for existing usage.

src/index.ts

@@ -1074,7 +1074,7 @@ class ThreadPool {
   }
 }
 
-class Piscina extends EventEmitterAsyncResource {
+export default class Piscina extends EventEmitterAsyncResource {
   #pool : ThreadPool;
 
   constructor (options : Options = {}) {
@@ -1346,4 +1346,14 @@ class Piscina extends EventEmitterAsyncResource {
   static get queueOptionsSymbol () { return kQueueOptions; }
 }
 
-export = Piscina;
+export const move = Piscina.move;
+export const isWorkerThread = Piscina.isWorkerThread;
+export const workerData = Piscina.workerData;
+
+export {
+  Piscina,
+  kTransferable as transferableSymbol,
+  kValue as valueSymbol,
+  kQueueOptions as queueOptionsSymbol,
+  version,
+}