Add more tsdoc comments

packages/lib/src/Emitter.ts

@@ -1,6 +1,15 @@
 import {EventEmitter} from 'events'
 
+/**
+ * Extended EventEmitter that also emits all events to '*' listeners
+ */
 export class Emitter extends EventEmitter {
+  /**
+   * Emits an event to listeners and to '*' listeners
+   * @param type - Event type/name
+   * @param args - Arguments to pass to listeners
+   * @returns True if event had listeners
+   */
   emit(type: string, ...args: any[]) {
     const a = super.emit(type, ...args)
     const b = super.emit('*', type, ...args)