Update README.md

Link to Material Symbols directory.

Author: tphinney

font/README.md

@@ -1,4 +1,6 @@
-This is the directory for Material Icons and Material Symbols. Material Icons are the non-variable classic icon fonts, while the new Material Symbols variable fonts offer weight, optical size, grade and fill variations (with grade and Fill being intended also for animated effects).
+This is the directory for Material Icons; the newer Material Symbols are at [../variablefont](https://github.com/google/material-design-icons/tree/master/variablefont).
+
+Material Icons are the non-variable classic icon fonts, while the Material Symbols variable fonts offer weight, optical size, grade and fill variations (with grade and Fill being intended also for animated effects).
 
 The recommended way to use the Material Icons font is by linking to the web font hosted on Google Fonts: