Add C# documentation for connecting to GDScript signals with parameters

[TheSecondReal0]

I'm in the process of converting parts of my game to C#, and had trouble figuring out how to connect to GDScript signals that had parameters. I've updated the cross language scripting page to include the solution that worked for me.

I'm not sure of the best way to explain why you need to explicitly create a new System.Action, maybe explaining that it needs more type information to know which method to call? Any feedback on that would be much appreciated!