Add github repo link in the footer (#5204)

beta/src/components/Icon/IconGitHub.tsx

@@ -8,10 +8,11 @@ export const IconGitHub = memo<JSX.IntrinsicElements['svg']>(
   function IconGitHub(props) {
     return (
       <svg
-        width="1em"
+        xmlns="http://www.w3.org/2000/svg"
+        width="1.33em"
+        height="1.33em"
+        viewBox="0 -2 24 24"
         fill="currentColor"
-        height="1em"
-        viewBox="0 0 20 20"
         {...props}>
         <path d="M10 0a10 10 0 0 0-3.16 19.49c.5.1.68-.22.68-.48l-.01-1.7c-2.78.6-3.37-1.34-3.37-1.34-.46-1.16-1.11-1.47-1.11-1.47-.9-.62.07-.6.07-.6 1 .07 1.53 1.03 1.53 1.03.9 1.52 2.34 1.08 2.91.83.1-.65.35-1.09.63-1.34-2.22-.25-4.55-1.11-4.55-4.94 0-1.1.39-1.99 1.03-2.69a3.6 3.6 0 0 1 .1-2.64s.84-.27 2.75 1.02a9.58 9.58 0 0 1 5 0c1.91-1.3 2.75-1.02 2.75-1.02.55 1.37.2 2.4.1 2.64.64.7 1.03 1.6 1.03 2.69 0 3.84-2.34 4.68-4.57 4.93.36.31.68.92.68 1.85l-.01 2.75c0 .26.18.58.69.48A10 10 0 0 0 10 0"></path>
       </svg>

beta/src/components/Layout/Footer.tsx

@@ -9,6 +9,7 @@ import ButtonLink from 'components/ButtonLink';
 import {ExternalLink} from 'components/ExternalLink';
 import {IconFacebookCircle} from 'components/Icon/IconFacebookCircle';
 import {IconTwitter} from 'components/Icon/IconTwitter';
+import {IconGitHub} from 'components/Icon/IconGitHub';
 import {IconNavArrow} from 'components/Icon/IconNavArrow';
 
 export function Footer() {
@@ -160,6 +161,12 @@ export function Footer() {
                   className={socialLinkClasses}>
                   <IconTwitter />
                 </ExternalLink>
+                <ExternalLink
+                  aria-label="React on Github"
+                  href="https://github.com/reactjs/reactjs.org"
+                  className={socialLinkClasses}>
+                  <IconGitHub />
+                </ExternalLink>
               </div>
             </div>
           </div>