Add webfonts directory to manifest.json

spectabular/manifest.json

@@ -9,6 +9,7 @@
 		"default_popup": "twig/browser-action.html"
 	},
 	"web_accessible_resources": [
-		"twig/*.html.twig"
+		"twig/*.html.twig",
+		"webfonts/*"
 	]
 }