Retain SkriptEventInfo#since(String) for compatibility

Not worth breaking addons

Author: APickledWalrus

src/main/java/ch/njol/skript/lang/SkriptEventInfo.java

@@ -122,6 +122,16 @@ public SkriptEventInfo<E> keywords(String... keywords) {
 		return this;
 	}
 
+	/**
+	 * Only used for Skript's documentation.
+	 *
+	 * @param since The version this event was added in
+	 * @return This SkriptEventInfo object
+	 */
+	public SkriptEventInfo<E> since(String since) {
+		return since(new String[]{since});
+	}
+
 	/**
 	 * Only used for Skript's documentation.
 	 *