Minecraft plugin is not loading?

I'm bored and wanted to try Java again, a Minecraft plugin.

I watched tutorials and simply followed them bluntly. Now I have the problem that my plugin doesn't have a red X in the code, but it doesn't load in Minecraft.

I would be happy if you could help me!

Codes and folder structure:

package me.Elias.geil;
import org.bukkit.plugin.java.JavaPlugin;

import me.Elias.geil.commands.HealCommand;

public class Main extends JavaPlugin {

public void onEnable ()
{
getCommand ("heal"). SetExecutor (new HealCommand ());
}

}

package me.Elias.geil.commands;
import org.bukkit.command.Command; import org.bukkit.command.CommandExecutor; import org.bukkit.command.CommandSender; import org.bukkit.entity.Player;

public class HealCommand implements CommandExecutor {

@Override
public boolean onCommand (CommandSender sender, Command cmd, String label, String [] args) {

if (sender instanceof player)
{
Player player = (player) transmitter;
player.setHealth (20);
player.setFoodLevel (20);
player.sendMessage ("§aYou are healthy yay.");

}

else
{
sender.sendMessage ("helo");
}
return true;
}

}

name: beautiful plugin
version: 1.0
main: me.Elias.geil.Main

commands:
heal:

The plugin.yml must be in the src folder. And the Permissions.yml doesn't matter. It says "permissions.yml is empty. Ignoring it". This comes from Bukkit and just says that the Bukkit file is empty.

Thanks alot! Everything works as it should!