added a tabcomplete for the PLAYER argument type

Author: DatAsianBoi123

src/main/java/com/datasiqn/commandcore/argument/type/PlayerArgumentType.java

@@ -1,11 +1,15 @@
 package com.datasiqn.commandcore.argument.type;
 
+import com.datasiqn.commandcore.command.CommandContext;
 import com.datasiqn.resultapi.None;
 import com.datasiqn.resultapi.Result;
 import org.bukkit.Bukkit;
 import org.bukkit.entity.Player;
 import org.jetbrains.annotations.NotNull;
 
+import java.util.List;
+import java.util.stream.Collectors;
+
 class PlayerArgumentType implements SimpleArgumentType<Player> {
     @Override
     public @NotNull String getTypeName() {
@@ -16,4 +20,9 @@ class PlayerArgumentType implements SimpleArgumentType<Player> {
     public @NotNull Result<Player, None> parseWord(String word) {
         return Result.ofNullable(Bukkit.getPlayerExact(word), None.NONE);
     }
+
+    @Override
+    public @NotNull List<String> getTabComplete(@NotNull CommandContext context) {
+        return Bukkit.getOnlinePlayers().stream().map(Player::getName).collect(Collectors.toList());
+    }
 }