Add Help subcommand

Author: adwsingh

mcp/mcp-cli/src/main/java/software/amazon/smithy/java/mcp/cli/McpCli.java

@@ -8,6 +8,7 @@
 import java.util.List;
 import java.util.ServiceLoader;
 import picocli.CommandLine;
+import picocli.CommandLine.HelpCommand;
 import software.amazon.smithy.java.mcp.cli.commands.Configure;
 import software.amazon.smithy.java.mcp.cli.commands.CreateBundle;
 import software.amazon.smithy.java.mcp.cli.commands.CreateGenericBundle;
@@ -37,6 +38,7 @@ public static void main(String[] args) {
                 .addSubcommand(new CreateGenericBundle());
         discoverCreateBundleCommands().forEach(createCommand::addSubcommand);
         var commandLine = new CommandLine(new McpRegistry())
+                .addSubcommand(new HelpCommand())
                 .addSubcommand(new StartServer())
                 .addSubcommand(new ListBundles())
                 .addSubcommand(new InstallBundle())

mcp/mcp-cli/src/main/java/software/amazon/smithy/java/mcp/cli/McpRegistry.java

@@ -6,7 +6,8 @@
 package software.amazon.smithy.java.mcp.cli;
 
 import picocli.CommandLine;
+import picocli.CommandLine.Command;
 
-@CommandLine.Command(name = "mcp-registry", versionProvider = VersionProvider.class, mixinStandardHelpOptions = true,
+@Command(name = "mcp-registry", versionProvider = VersionProvider.class, mixinStandardHelpOptions = true,
         scope = CommandLine.ScopeType.INHERIT)
 final class McpRegistry {}