refactor(eio-client): improve JSDoc documentation

Author: darrachequesne

packages/engine.io-client/lib/socket.ts

@@ -795,7 +795,7 @@ export class SocketWithoutUpgrade extends Emitter<
   /**
    * Sends a packet.
    *
-   * @param {String} type: packet type.
+   * @param {String} type - packet type.
    * @param {String} data.
    * @param {Object} options.
    * @param {Function} fn - callback function.

packages/engine.io-client/lib/transports/polling-xhr.ts

@@ -52,11 +52,11 @@ export abstract class BaseXHR extends Polling {
   /**
    * Sends data.
    *
-   * @param {String} data to send.
-   * @param {Function} called upon flush.
+   * @param {String} data - data to send.
+   * @param {Function} fn - called upon flush.
    * @private
    */
-  override doWrite(data, fn) {
+  override doWrite(data: string, fn: () => void) {
     const req = this.request({
       method: "POST",
       data: data,