Resolve "Fix font assets path"

Closes #10 (closed)

pubspec.yaml

@@ -38,11 +38,11 @@ flutter:
   fonts:
     - family: Nunito
       fonts:
-        - asset: assets/fonts/Nunito-Bold.ttf
+        - asset: packages/flutter_custom_toolbox/fonts/Nunito-Bold.ttf
           weight: 700
-        - asset: assets/fonts/Nunito-Medium.ttf
+        - asset: packages/flutter_custom_toolbox/fonts/Nunito-Medium.ttf
           weight: 500
-        - asset: assets/fonts/Nunito-Regular.ttf
+        - asset: packages/flutter_custom_toolbox/fonts/Nunito-Regular.ttf
           weight: 400
-        - asset: assets/fonts/Nunito-Light.ttf
+        - asset: packages/flutter_custom_toolbox/fonts/Nunito-Light.ttf
           weight: 300