title: VSCode User Snippet not working inside other snippet
body: <p>I created some VSCode User Snippet, but it not working inside other snippet.</p>
  
  <p>This is newest version of VSCode, 1.36.</p>
  
  <p>If I have this snippet,</p>
  
  <pre><code>    "tmp": {
          "prefix": "tmp",
          "body": [
              "#include &lt;bits/stdc++.h&gt;",
              "using namespace std;",
              "",
              "int main()",
              "{",
              "    ${1:int} ans;",
              "    ${2:/* code */}",
              "    return 0;",
              "}"
          ],
          "description": "template"
      },
  </code></pre>
  
  <p>and trying this snippet inside $2 above,</p>
  
  <pre><code>    "cin1": {
          "prefix": "cin1",
          "body": [
              "int a;",
              "cin &gt;&gt; a;"
          ],
          "description": "template"
      },
  </code></pre>
  
  <p>it never works, and show nothing in completion.</p>
  
  <p>I'd like to show completion inside snippet.
  Any helps are appreciated.</p>