Add a custom button on Navigation menu

[AlienCreature7]

I know it's possible using the library repo but it would be awesome if it was possible to do it even using the sample project.

Just a simple button that opens a link. Really useful if the app has a separate paid version.

[danimahardhika]

I don't know if it's really needed by others. I'll considering about this and keep the issue open.

[AlienCreature7]

@danimahardhika I actually added this to my app but it can be a useful feature.