Added BlueSpider and RedSpider

Added healing for RedSpider

BlueSpider.java

@@ -0,0 +1,18 @@
+import greenfoot.World;
+
+public class BlueSpider extends Spider {
+    private World w;
+
+    public BlueSpider() {
+        super();
+    }
+
+    public void addedToWorld(World w) {
+        this.w = w;
+    }
+
+    public void act() {
+        super.act();
+    }
+
+}

RedSpider.java

@@ -0,0 +1,27 @@
+import greenfoot.World;
+
+import java.util.Objects;
+
+public class RedSpider extends Spider {
+    private World w;
+
+    public RedSpider() {
+        super();
+        healPlayer();
+    }
+
+    public void addedToWorld(World w) {
+        this.w = w;
+    }
+
+    private void healPlayer() {
+        if (w == null) {
+            return;
+        }
+        Player topL = (Player) getOneObjectAtOffset(-(getImage().getWidth() / 2), getImage().getHeight() / 2, Player.class);
+        Player topR = (Player) getOneObjectAtOffset(getImage().getWidth() / 2, getImage().getHeight() / 2, Player.class);
+        if (topL != null || topR != null) {
+            Objects.requireNonNullElse(topL, topR).changeHP(+1);
+        }
+    }
+}

Spider.java

@@ -4,10 +4,9 @@ public class Spider extends Mobs {
     private final int hp;
     private final double speed;
     private final int dmg;
-    public World w;
-    long startTime;
-    long elapsedTime;
-    boolean oob = false;
+    private World w;
+    private long startTime;
+    private boolean oob = false;
 
     public Spider() {
         hp = 2;
@@ -35,7 +34,7 @@ public void timeout() {
             oob = false;
         }
         if (oob) {
-            elapsedTime = System.currentTimeMillis() - startTime;
+            long elapsedTime = System.currentTimeMillis() - startTime;
             if (elapsedTime > 10 * 1000) {
                 w.removeObject(this);
             }