Add fip-validity to shortcut tiles

[lenderom]

We should add the fip-validity page here. Otherwise the page is very difficult to find

[lenderom]

I had a second thought about this. I don't know how to call the site properly. In #777 I changed the title to "FIP Validity" but is this really the topic of the site. At the moment this page is a summary of all information which are dependent on your FIP card issuer... And furthermore, should we add this site also to the navigation bar/side menu?

Also, how do we handle the taxation site?