Add an informal enumeration that lists all kinds of Markdom nodes

Author: Torsten Krause

module/core/src/main/java/io/markdom/common/MarkdomNodeKind.java

@@ -0,0 +1,37 @@
+package io.markdom.common;
+
+public enum MarkdomNodeKind {
+
+	DOCUMENT,
+
+	CODE_BLOCK,
+
+	COMMENT_BLOCK,
+
+	DIVISION_BLOCK,
+
+	HEADING_BLOCK,
+
+	ORDERED_LIST_BLOCK,
+
+	PARAGRAPH_BLOCK,
+
+	QUOTE_BLOCK,
+
+	UNORDERED_LIST_BLOCK,
+	
+	LIST_ITEM,
+	
+	CODE_CONTENT,
+
+	EMPHASIS_CONTENT,
+
+	IMAGE_CONTENT,
+
+	LINE_BREAK_CONTENT,
+
+	LINK_CONTENT,
+
+	TEXT_CONTENT;
+
+}