docs(index): add favicon to home page

Fix #8226

index.pug

@@ -9,6 +9,24 @@ html(lang='en')
     link(href="docs/css/style.css", rel="stylesheet")
     link(href="/docs/css/github.css", rel="stylesheet")
 
+    link(rel='apple-touch-icon', sizes='57x57', href='docs/images/favicon/apple-icon-57x57.png')
+    link(rel='apple-touch-icon', sizes='60x60', href='docs/images/favicon/apple-icon-60x60.png')
+    link(rel='apple-touch-icon', sizes='72x72', href='docs/images/favicon/apple-icon-72x72.png')
+    link(rel='apple-touch-icon', sizes='76x76', href='docs/images/favicon/apple-icon-76x76.png')
+    link(rel='apple-touch-icon', sizes='114x114', href='docs/images/favicon/apple-icon-114x114.png')
+    link(rel='apple-touch-icon', sizes='120x120', href='docs/images/favicon/apple-icon-120x120.png')
+    link(rel='apple-touch-icon', sizes='144x144', href='docs/images/favicon/apple-icon-144x144.png')
+    link(rel='apple-touch-icon', sizes='152x152', href='docs/images/favicon/apple-icon-152x152.png')
+    link(rel='apple-touch-icon', sizes='180x180', href='docs/images/favicon/apple-icon-180x180.png')
+    link(rel='icon', type='image/png', sizes='192x192',  href='docs/images/favicon/android-icon-192x192.png')
+    link(rel='icon', type='image/png', sizes='32x32', href='docs/images/favicon/favicon-32x32.png')
+    link(rel='icon', type='image/png', sizes='96x96', href='docs/images/favicon/favicon-96x96.png')
+    link(rel='icon', type='image/png', sizes='16x16', href='docs/images/favicon/favicon-16x16.png')
+    link(rel='manifest', href='docs/images/favicon/manifest.json')
+    meta(name='msapplication-TileColor', content='#ffffff')
+    meta(name='msapplication-TileImage', content='docs/images/favicon/ms-icon-144x144.png')
+    meta(name='theme-color', content='#ffffff')
+
     style.
       code {
         font-size: 1em;