Added the help command

This command prints a list of all commands which are available

src/main/java/org/bitbiome/commands/CommandListener.java

@@ -10,13 +10,7 @@ public class CommandListener {
     public CommandListener() {
         commands = new HashMap<>();
 
-        /*
-        * Commandfield
-        *
-        * commands.put("CommandName", new CommandClass());
-        *
-        *
-         */
+        commands.put("help", new HelpCommand());
     }
 
     public HashMap<String, CommandAPI> returnCommands() {

src/main/java/org/bitbiome/commands/HelpCommand.java

@@ -0,0 +1,22 @@
+package org.bitbiome.commands;
+
+import org.bitbiome.Boot;
+
+import java.util.HashMap;
+import java.util.Scanner;
+
+public class HelpCommand implements CommandAPI {
+
+
+    @Override
+    public void performCommand(Scanner scanner, boolean isRunning, String message) {
+        HashMap<String, CommandAPI> commands = Boot.instance.getCmdListener().returnCommands();
+        StringBuilder outputMessage = new StringBuilder();
+        outputMessage.append("Hier ist eine Liste der Commands:\n");
+        commands.forEach((key, value) -> {
+            outputMessage.append("- ").append(key).append("\n");
+        });
+        System.out.println(outputMessage.toString());
+    }
+
+}