Add methods for Armadillo (#12031)

paper-api/src/main/java/org/bukkit/entity/Armadillo.java

@@ -1,8 +1,38 @@
 package org.bukkit.entity;
 
+import org.jspecify.annotations.NullMarked;
+
 /**
  * Represents an Armadillo.
  */
+@NullMarked
 public interface Armadillo extends Animals {
 
+    /**
+     * Get the current state of the armadillo.
+     *
+     * @return the state of the armadillo
+     */
+    State getState();
+
+    /**
+     * Attempt to roll up if the armadillo is {@link State#IDLE}
+     */
+    void rollUp();
+
+    /**
+     * Attempt to roll out if the armadillo is not {@link State#IDLE}
+     */
+    void rollOut();
+
+    /**
+     * Represents the current state of the armadillo.
+     */
+    enum State {
+        IDLE,
+        ROLLING,
+        SCARED,
+        UNROLLING;
+    }
+
 }