UseHost() - can't have subcommand "config"

[seanadams9]

When using UseHost() the hosting action sets up a CliDirective with the name "config". If you have a subcommand with the same name "config" parsing fails with:

An item with the same key has already been added. Key: config
System.ArgumentException: An item with the same key has already been added. Key: config
at System.Collections.Generic.Dictionary2.TryInsert(TKey key, TValue value, InsertionBehavior behavior) at System.Collections.Generic.Dictionary2.Add(TKey key, TValue value)
at System.CommandLine.Parsing.StringExtensions.g__AddCommandTokens|8_0(Dictionary2 tokens, CliCommand cmd) at System.CommandLine.Parsing.StringExtensions.ValidTokens(CliCommand command, IReadOnlyList1 directives)
at System.CommandLine.Parsing.StringExtensions.Tokenize(IReadOnlyList1 args, CliConfiguration configuration, Boolean inferRootCommand, List1& tokens, List1& errors) at System.CommandLine.Parsing.CliParser.Parse(CliCommand command, IReadOnlyList1 arguments, String rawInput, CliConfiguration configuration)
at System.CommandLine.Parsing.CliParser.Parse(CliCommand command, IReadOnlyList1 args, CliConfiguration configuration) at System.CommandLine.CliConfiguration.Parse(IReadOnlyList1 args)

[jonsequitur]

This bug is more general and affects any directive where the name collides with a command defined on the root.