change package manager to pnpm, change type definition

scripts/generate-declarations.js

@@ -112,6 +112,7 @@ function generateDeclarations(classNames) {
  */
 type CreatableInstancesWithConstructors = {
     [K in keyof CreatableInstances]: {
+        new (parent?: Instance): CreatableInstances[K];
         new (...args: any[]): CreatableInstances[K];
     }
 }