vscode的插件想离线安装，则先需要先行下载

• 插件官网

  https://marketplace.visualstudio.com/vscode

• 下载链接的模板

  https://${publisher}.gallery.vsassets.io/_apis/public/gallery/publisher/${publisher}/extension/${extension name}/${version}/assetbyname/Microsoft.VisualStudio.Services.VSIXPackage

• 举例说明（Python插件）
  Python插件页面

  https://marketplace.visualstudio.com/items?itemName=ms-python.python

  其中
  ${publisher}的值为ms-python
  ${extension name}的值为python
  ${version}的值在界面右侧的More Info获取(当前版本是2018.6.0)
  Python下载链接

  https://ms-python.gallery.vsassets.io/_apis/public/gallery/publisher/ms-python/extension/python/2018.2.1/assetbyname/Microsoft.VisualStudio.Services.VSIXPackage

  说明：下载之后的文件名是Microsoft.VisualStudio.Services.VSIXPackage，可修改文件名为python.vsix(文件名随意修改，后缀必须为vsix)
  个人常用下载地址

  Python
  https://ms-python.gallery.vsassets.io/_apis/public/gallery/publisher/ms-python/extension/python/2018.6.0/assetbyname/Microsoft.VisualStudio.Services.VSIXPackage
  Markdown All in One
  https://yzhang.gallery.vsassets.io/_apis/public/gallery/publisher/yzhang/extension/markdown-all-in-one/1.4.0/assetbyname/Microsoft.VisualStudio.Services.VSIXPackage
  Markdown PDF
  https://yzane.gallery.vsassets.io/_apis/public/gallery/publisher/yzane/extension/markdown-pdf/1.2.0/assetbyname/Microsoft.VisualStudio.Services.VSIXPackage
  markdownlint
  https://DavidAnson.gallery.vsassets.io/_apis/public/gallery/publisher/DavidAnson/extension/vscode-markdownlint/0.18.0/assetbyname/Microsoft.VisualStudio.Services.VSIXPackage
  vscode-icons
  https://robertohuertasm.gallery.vsassets.io/_apis/public/gallery/publisher/robertohuertasm/extension/vscode-icons/7.23.0/assetbyname/Microsoft.VisualStudio.Services.VSIXPackage