Sorry, I misunderstood the question - Erik is right, we've previously talked about implementing that.
In other words, my response still is correct: you'd want to take a look at airports.xml (which is where we have an airports/runway diagram) and port that into a MapStructure layer, that should typically take 1 hour at most (since the underlying code is already using Nasal and Canvas). At that point, all you need is adding 3 lines of code to the ND to display the airport/runway diagram there.
With that being said, that's only relevant if people haven't already come up with such a layer, like Erik said.
Just to be clear about it, open the airports.xml dialog (in-sim) to see for yourself that we already have the required functionality (styling, colors, appearance) can be easily customized as needed.
Making THAT display show up in-sim on an ND really is very straightforward to do.
If in doubt, check whether the FG1000 already has support for this, because Stuart implemented both features originally, so if it's been done already, he would be aware of it (or send him a message or post to the devel mailing list before starting any work).
How to display Airport Chart?