Move to a single top-level file

[cartermp]

This compiles, but fails at runtime with:

Building...
Unhandled exception. System.InvalidOperationException: Action must have a pattern. Is it missing a Route attribute?
   at Microsoft.AspNetCore.Builder.MapActionEndpointRouteBuilderExtensions.MapAction(IEndpointRouteBuilder endpoints, Delegate action)
   at Program.main(String[] args) in /Users/phillip/repos/HoudiniPlaygroundFSharp/Program.fs:line 18

[halter73]

Love it! I went a bit into the reason for the error in #1 (comment)

I would have thought #1 had a better chance of working since it's constructing the Funcs with a direct reference to a method on the Startup class/type, though this looks a lot better. If we could make reasonable MethodInfos out of locally define functions that would be amazing!