PrefixedKeyConsoleHelpWriter is abstract but shouldn't be

[akamsteeg]

Currently, PrefixedKeyConsoleHelpWriter is an abstract class:

AtleX.CommandLineArguments/src/AtleX.CommandLineArguments/Help/PrefixedKeyConsoleHelpWriter.cs

Line 8 in cdf8fc5

public abstract class PrefixedKeyConsoleHelpWriter

However, I don't think that it should be. It's a complete implementation of IHelpWriter that can work on its own. Now we're forcing people to extend it, just to call the constructor of the abstract base class PrefixedKeyConsoleHelpWriter. It's clean, because it forces strong-typed help writers, but it also makes introducing a new one for a 3rd-party thing much more involved.

Suggestion: Remove the abstract modified from PrefixedKeyConsoleHelpWriter.