update description and keywords

Author: Cube-J

1.hello-world/4.read-video-react/public/index.html

@@ -5,10 +5,9 @@
     <link rel="icon" href="%PUBLIC_URL%/favicon.ico" />
     <meta name="viewport" content="width=device-width, initial-scale=1" />
     <meta name="theme-color" content="#000000" />
-    <meta
-      name="description"
-      content="Web site created using create-react-app"
-    />
+    <meta name="description" content="Read barcode with Dynamsoft Barcode Reader in a React Application.">
+    <meta name="keywords" content="read barcode from camera and images in React">
+    <link rel="canonical" href="https://demo.dynamsoft.com/Samples/DBR/JS/1.hello-world/4.read-video-react/build/">
     <link rel="apple-touch-icon" href="%PUBLIC_URL%/logo192.png" />
     <!--
       Notice the use of %PUBLIC_URL% in the tags above.