feat(task): any data can be attached to the task

Previously, only `name` was accepted.

@vates/task/.USAGE.md

@@ -2,7 +2,12 @@
 import { Task } from '@vates/task'
 
 const task = new Task({
-  name: 'my task',
+  // data in this object will be sent along the *start* event
+  //
+  // property names should be chosen as not to clash with properties used by `Task` or `combineEvents`
+  data: {
+    name: 'my task',
+  },
 
   // if defined, a new detached task is created
   //

@vates/task/README.md

@@ -18,7 +18,12 @@ npm install --save @vates/task
 import { Task } from '@vates/task'
 
 const task = new Task({
-  name: 'my task',
+  // data in this object will be sent along the *start* event
+  //
+  // property names should be chosen as not to clash with properties used by `Task` or `combineEvents`
+  data: {
+    name: 'my task',
+  },
 
   // if defined, a new detached task is created
   //

@vates/task/index.js

@@ -84,8 +84,8 @@ exports.Task = class Task {
     return this.#status
   }
 
-  constructor({ name, onProgress }) {
-    this.#startData = { name }
+  constructor({ data = {}, onProgress }) {
+    this.#startData = data
 
     if (onProgress !== undefined) {
       this.#onProgress = onProgress