chore: have a single resources dir

Author: lukester1975

package.json

@@ -2,7 +2,7 @@
   "name": "mesonbuild",
   "displayName": "Meson",
   "description": "Meson language support for Visual Studio Code",
-  "icon": "graphics/icon.png",
+  "icon": "res/icon.png",
   "version": "1.5.0-devel",
   "license": "Apache-2.0",
   "publisher": "mesonbuild",