F# API Documentation Examples

While our machinelearning-samples repo has F# samples, the ML.Net API documentation examples do not contain F# examples.

This is a work item to add F# examples to demonstrate API usage and to mirror what we have in C#.

Things that need to be understood:
1) Does our current documentation pipeline support another language (we support python and C#, can we add F# examples and have it work or is there some additional work that needs to be done? If so, lets create an issue -- following up with @JRAlexander and @natke)

2) If it is supported, is there a specific directory structure or other restrictions that need to be followed?

If there are sub-issues that need to be created, please use this as the global issue for tracking.

cc @shmoradims, @sfilipi, @zeahmed, @rogancarr