在app.json的pages里要注明你编辑的网页地址

"pages": [
     //以下两行是原有的代码
      "pages/index/index",
      "pages/logs/logs",
    //以下三行是我自己新加的网页路径
    "pages/learn_wxml/learn_wxml",
    "pages/main/main",
    "pages/prepare/prepare"
  ],