开发一个微信小程序，输出九九乘法口决表。

好的，以下是九九乘法口诀表的微信小程序代码：

//index.js
Page({
  data: {
    multiplicationTable: []
  },
  onLoad: function () {
    var multiplicationTable = []
    for (var i = 1; i <= 9; i++) {
      var row = []
      for (var j = 1; j <= i; j++) {
        row.push(j + "*" + i + "=" + j * i)
      }
      multiplicationTable.push(row)
    }
    this.setData({
      multiplicationTable: multiplicationTable
    })
  }
})

<!--index.wxml-->
<view class="container">
  <view class="row" wx:for="{{multiplicationTable}}" wx:key="index">
    <view wx:for="{{item}}" wx:key="index" class="cell">{{item}}</view>
  </view>
</view>

/*index.wxss*/
.container {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.row {
  display: flex;
  flex-direction: row;
  justify-content: center;
  margin-bottom: 10px;
}

.cell {
  width: 50px;
  height: 50px;
  line-height: 50px;
  text-align: center;
  border: 1px solid #ccc;
  margin-right: 10px;
}

这个小程序会在页面加载时生成九九乘法口诀表，并在页面中显示出来。