[docs] Font vs SVG. Which approach to use? (#12466)

* Update icons.md

* all good for me

Author: PolGuixe

docs/src/pages/style/icons/icons.md

@@ -107,3 +107,10 @@ Optionally, you can set the icon color using one of the theme color properties:
 ### [Font Awesome](https://fontawesome.com/icons)
 
 {{"demo": "pages/style/icons/FontAwesome.js", "hideEditButton": true}}
+
+## Font vs SVG. Which approach to use?
+
+Both approaches work fine, however, there are some subtle differences, especially in terms of performance and rendering quality.
+Whenever possible SVG is preferred as it allows code splitting, supports more icons, renders faster and better.
+
+For more details, you can check out [why GiHub migrated](https://blog.github.com/2016-02-22-delivering-octicons-with-svg/) from font icons to SVG icons.