Handling of greater than 8 inputs

This release provides a convenient way to handle commands that require more than 8 inputs via the new add custom operation on the rootCommand and command builders.

Additional info

Currently, a command handler function is limited to accept a tuple with no more than eight inputs.
If you need more than eight inputs, you can now pass in the InvocationContext to your handler, which will allow you manually get as many input values as you like (assuming they have been registered via the rootCommand or command builder's add operation:

module Program

open FSharp.SystemCommandLine

module Parameters = 
    let words = Input.Option<string[]>(["--word"; "-w"], Array.empty, "A list of words to be appended")
    let separator = Input.OptionMaybe<string>(["--separator"; "-s"], "A character that will separate the joined words.")

let app (ctx: System.CommandLine.Invocation.InvocationContext) =
    // Manually parse as many parameters as you need
    let words = Parameters.words.GetValue ctx
    let separator = Parameters.separator.GetValue ctx

    // Do work
    let separator = separator |> Option.defaultValue ", "
    System.String.Join(separator, words) |> printfn "Result: %s"
    0
    
[<EntryPoint>]
let main argv = 
    let ctx = Input.Context()

    rootCommand argv {
        description "Appends words together"
        inputs ctx
        setHandler app
        add Parameters.words
        add Parameters.separator
    }

Caveats

This manual binding mechanism is less type safe because the compiler has no way to determine if you have manually added all input parameters to the command; so if you forget to add one that is used, it will result in a runtime error.

(For this reason, you should try to limit your commands to 8 parameters when possible, by factoring your app into separate commands.)