[CI-SKIP] Add JavaDoc links to Tag class pointing to custom Paper tags (#5285)

Spigot-API-Patches/Add-Material-Tags.patch

@@ -943,6 +943,21 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
 +        .add(DOLPHIN, SQUID, GUARDIAN, ELDER_GUARDIAN, TURTLE, COD, SALMON, PUFFERFISH, TROPICAL_FISH)
 +        .ensureSize("WATER_BASED", 9);
 +}
+diff --git a/src/main/java/org/bukkit/Tag.java b/src/main/java/org/bukkit/Tag.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/org/bukkit/Tag.java
++++ b/src/main/java/org/bukkit/Tag.java
+@@ -0,0 +0,0 @@ import org.jetbrains.annotations.NotNull;
+  * Note that whilst all tags defined within this interface must be present in
+  * implementations, their existence is not guaranteed across future versions.
+  *
++ * <p>Custom tags defined by Paper are not present (as constants) in this class.
++ * To access them please refer to {@link com.destroystokyo.paper.MaterialTags}
++ * and {@link io.papermc.paper.tag.EntityTags}.</p>
++ *
+  * @param <T> the type of things grouped by this tag
+  */
+ public interface Tag<T extends Keyed> extends Keyed {
 diff --git a/src/test/java/com/destroystokyo/paper/MaterialTagsTest.java b/src/test/java/com/destroystokyo/paper/MaterialTagsTest.java
 new file mode 100644
 index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000