title: Missing tsconfig.json file and Experimental Decorators warning in vsCode
body: <p>In <code>Angular 6.0.3</code> (<code>global Angular CLI v6.0.8</code>, <code>local Angular CLI v6.0.7</code>) I'm suddenly getting intellisense errors on every component that I open: <em><code>Experimental support for decorators is a feature that is subject to change in a future release. Set the 'experimentalDecorators' option to remove this warning.</code></em> </p>
  
  <p>I've tried the instructions from the accepted answer here: <a href="https://stackoverflow.com/questions/38271273/experimental-decorators-warning-in-typescript-compilation">Experimental decorators warning in TypeScript compilation</a></p>
  
  <p>But my tsconfig.json file already had <code>"experimentalDecorators": true</code>.</p>
  
  <p>I've also tried closing and re-opening <code>visual studio code</code>, clicking the <code>refresh</code> button on the file tree, <code>Reload Window</code> command etc etc ad nauseum. 
  I think my issue may lie in the fact that I can't see <code>tsconfig.json</code> anywhere in my file structure (so perhaps neither can Angular). I believe it does exist because I do see <code>tsconfig.app.json</code> and this file has a link to <code>tsconfig.json</code> which I can <code>ctrl + click</code> to follow to the <code>tsconfig.json</code> file. </p>
  
  <p><strong>How can I find the location of <code>tsconfig.json</code> and/or make it appear at the same file level as <code>tsconfig.app.json</code> like the rest of my dev team has?</strong></p>
  
  <p>My <code>tsconfig.app.json</code> file:</p>
  
  <pre><code>{
    "extends": "../tsconfig.json",  //I can ctrl + click here to go to tsconfig.json
    "compilerOptions": {
      "outDir": "../out-tsc/app",
      "module": "es2015",
      "types": []
    },
    "exclude": [
      "src/test.ts",
      "**/*.spec.ts"
    ]
  }  
  </code></pre>
  
  <p>My (missing/invisible) <code>tsconfig.json</code> file:</p>
  
  <pre><code>{
    "compileOnSave": false,
    "compilerOptions": {
      "baseUrl": "./",
      "outDir": "./dist/out-tsc",
      "sourceMap": true,
      "declaration": false,
      "moduleResolution": "node",
      "emitDecoratorMetadata": true,
      "experimentalDecorators": true,
      "target": "es5",
      "typeRoots": [
        "node_modules/@types"
      ],
      "lib": [
        "es2017",
        "dom"
      ]
    }
  }
  </code></pre>