title: How to use chartjs-plugin-annotation in Angular
body: <p>My versions in the Angular project are:
  "chart.js": "^2.9.2",
      "chartjs-plugin-annotation": "^0.5.7",</p>
  
  <p>On typing the import statement:</p>
  
  <pre><code>import * as ChartAnnotation from 'chartjs-plugin-annotation';
  </code></pre>
  
  <p>I am getting this on hovering above it</p>
  
  <pre><code>Could not find a declaration file for module 'chartjs-plugin-annotation'. 'c:/XRay/xray/node_modules/chartjs-plugin-annotation/src/index.js' implicitly has an 'any' type.
    Try `npm install @types/chartjs-plugin-annotation` if it exists or add a new declaration (.d.ts) file containing `declare module 'chartjs-plugin-annotation';`ts(7016)
  </code></pre>
  
  <p>I am trying to make a line on my scatter chart by using this</p>
  
  <pre class="lang-js prettyprint-override"><code>this.scatterChart = new Chart('myChart', {
  
          type: 'scatter',
          //plugins: [ChartAnnotation],
          data: {
              datasets: [{
                  label: 'Scatter Dataset',
                  pointBackgroundColor: ['yellow', 'blue', 'red', 'green', 'orange', 'indigo'],
  
                  data: [
                    { x: -10, y: 0 }, 
                      { x: 0, y: 10 }, 
                      { x: 3, y: 8 }, 
                      { x: 1, y: 4 }, 
                      { x: 9, y: 1 }, 
                      { x: -1, y: 5 }
                  ]
              }]
          },
          options: {
            legend: {
              display: false
            },
  
              scales: {
                  xAxes: [{
                      type: 'linear',
                      position: 'bottom'
                  }]
              },
              annotation:{
                drawTime: 'afterDatasetsDraw',
                annotations:[{
                type: 'line',
                id: 'vline',
                mode: 'horizontal',
                yscaleID: 'y-axis-0',
                value: 5,
                borderColor: 'green',
                borderWidth: 1,
                label: {
                  enabled: false,
                  content: 'Test label'
                }
              }]
            }
          } as ChartOptions
  
  
      });
  </code></pre>