title: Could not find a declaration file for module 'vue-xxx'
body: <p>Any 3rd party Vue.js library that I try to add to my project, throws the following error:</p>
  
  <pre><code>Could not find a declaration file for module 'vue-xxx'
  </code></pre>
  
  <p>I have tried 'vue-treeselect', 'vue-select'<em>, 'vue-multiselect'</em> with more or less the same result (* those libraries don't allow <code>import Modulename from</code>, but need <code>const Modulename = require</code>).</p>
  
  <p>I add those under <code>"dependencies": {</code> in <code>package.json</code>.</p>
  
  <p>I am using the SPA template for Vue.js provided by dotnet core.</p>
  
  <hr>
  
  <p>Full example with <a href="https://github.com/riophae/vue-treeselect" rel="noreferrer">'tree-select'</a>:</p>
  
  <pre><code>import Treeselect from 'vue-treeselect';
  
  /* ... */
  
  value = null;
  source = [
      {
          id: 'node-1',
          label: 'Node 1',
          children: [
              {
                  id: 'node-1-a',
                  label: 'Node 1-A',
              }
        ]
      },
      {
          id: 'node-2',
          label: 'Node 2',
      }
    ];
  
  /* ... */
  
  &lt;treeselect v-model="value"
                  :multiple="true"
                  :options="source" /&gt;
  </code></pre>
  
  <p>Error:</p>
  
  <pre><code>in [at-loader] ./ClientApp/components/mycomponent/mycomponent.ts:10:24 
      TS7016: Could not find a declaration file for module 'vue-treeselect'. 'path/to/project/node_modules/vue-treeselect/dist/vue-treeselect.js' implicitly has an 'any' type.
  </code></pre>
  
  <hr>
  
  <p>package.json </p>
  
  <pre><code>{
    "name": "MyProject",
    "private": true,
    "version": "0.0.0",
    "dependencies": {
      "dygraphs": "^2.1.0",
      "ol3-layerswitcher": "^1.1.2",
      "vue-treeselect": "^1.0.6"
    },
    "devDependencies": {
      "@types/dygraphs": "^1.1.6",
      "@types/webpack-env": "^1.13.0",
      "@types/vue": "^2.0.0",
      "aspnet-webpack": "^2.0.1",
      "awesome-typescript-loader": "^3.0.0",
      "bootstrap": "^3.3.6",
      "css-loader": "^0.25.0",
      "event-source-polyfill": "^0.0.7",
      "extract-text-webpack-plugin": "^2.0.0-rc",
      "file-loader": "^0.9.0",
      "isomorphic-fetch": "^2.2.1",
      "jquery": "^3.1.1",
      "style-loader": "^0.13.1",
      "typescript": "^2.2.1",
      "url-loader": "^0.5.7",
      "vue": "^2.5.13",
      "vue-loader": "^14.2.1",
      "vue-property-decorator": "^6.0.0",
      "vue-router": "^3.0.1",
      "vue-template-compiler": "^2.5.13",
      "webpack": "^2.2.0",
      "webpack-hot-middleware": "^2.12.2"    
    }
  }
  </code></pre>