Make slash commands interface and load them dynamically

Slash commands are now loaded dynamically by implementing a SlashCommand interface and storing them in a loaded commands map.

src/main/java/wtf/beatrice/hidekobot/commands/slash/PingCommand.java

@@ -2,9 +2,16 @@ package wtf.beatrice.hidekobot.commands.slash;
 
 import net.dv8tion.jda.api.events.interaction.command.SlashCommandInteractionEvent;
 import org.jetbrains.annotations.NotNull;
+import wtf.beatrice.hidekobot.objects.SlashCommand;
 
-public class PingCommand
+public class PingCommand implements SlashCommand
 {
+    @Override
+    public String getCommandName() {
+        return "ping";
+    }
+
+    @Override
     public void runSlashCommand(@NotNull SlashCommandInteractionEvent event)
     {
         event.reply("Pong!").queue();