Adds comments to all custom events

Adds full comments to every class implementing StarGateEvent
Adds another abstract event StargatePlayerEvent which reduces code duplication

src/main/java/net/knarcraft/stargate/event/StargateCloseEvent.java

@@ -4,33 +4,59 @@ import net.knarcraft.stargate.Portal;
 import org.bukkit.event.HandlerList;
 import org.jetbrains.annotations.NotNull;
 
+/**
+ * This event should be called whenever a stargate is closed
+ */
+@SuppressWarnings("unused")
 public class StargateCloseEvent extends StargateEvent {
 
     private boolean force;
 
     private static final HandlerList handlers = new HandlerList();
 
-    @NotNull
-    public HandlerList getHandlers() {
-        return handlers;
-    }
-
-    public static HandlerList getHandlerList() {
-        return handlers;
-    }
-
+    /**
+     * Instantiates a new stargate closing event
+     *
+     * @param portal <p>The portal to close</p>
+     * @param force  <p>Whether to force the gate to close, even if set as always-on</p>
+     */
     public StargateCloseEvent(Portal portal, boolean force) {
         super("StargateCloseEvent", portal);
 
         this.force = force;
     }
 
+    /**
+     * Gets whether to force the stargate to close
+     *
+     * @return <p>Whether to force the stargate to close</p>
+     */
     public boolean getForce() {
         return force;
     }
 
+    /**
+     * Sets whether the stargate should be forced to close
+     *
+     * @param force <p>Whether the stargate should be forced to close</p>
+     */
     public void setForce(boolean force) {
         this.force = force;
     }
 
+    /**
+     * Gets a handler-list containing all event handlers
+     *
+     * @return <p>A handler-list with all event handlers</p>
+     */
+    public static HandlerList getHandlerList() {
+        return handlers;
+    }
+
+    @NotNull
+    @Override
+    public HandlerList getHandlers() {
+        return handlers;
+    }
+
 }