Add CooldownTimer

Added the Cooldown Timer for when a user uses a Rabbit's Foot. This restricts a user from using rabbit's feet consecutively by forcing a 30 second cooldown between uses.

src/main/java/io/github/simplex/luck/util/CooldownTimer.java

@@ -0,0 +1,38 @@
+package io.github.simplex.luck.util;
+
+import io.github.simplex.lib.MiniComponent;
+import net.kyori.adventure.text.Component;
+import org.bukkit.entity.Player;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.UUID;
+import java.util.concurrent.TimeUnit;
+
+public class CooldownTimer {
+    private final Map<UUID, Long> cooldowns = new HashMap<>();
+
+    public static final long DEFAULT_COOLDOWN = 30L;
+
+    public void setCooldown(UUID playerUUID, long time) {
+        if (time < 1) {
+            cooldowns.remove(playerUUID);
+        } else {
+            cooldowns.put(playerUUID, time);
+        }
+    }
+
+    public long getCooldown(UUID uuid) {
+        return cooldowns.getOrDefault(uuid, 0L);
+    }
+
+    public long remaining(Player player) {
+        long timeLeft = System.currentTimeMillis() - getCooldown(player.getUniqueId());
+        return TimeUnit.MILLISECONDS.toSeconds(timeLeft) - DEFAULT_COOLDOWN;
+    }
+
+    public boolean onCooldown(Player player) {
+        long remaining = System.currentTimeMillis() - getCooldown(player.getUniqueId());
+        return (!(TimeUnit.MILLISECONDS.toSeconds(remaining) >= DEFAULT_COOLDOWN));
+    }
+}