add neo4j

README.md

@@ -19,6 +19,7 @@
 * C# 技能树：https://codechina.csdn.net/csdn/skill_tree_csharp
 * OpenCV 技能树：https://codechina.csdn.net/csdn/skill_tree_opencv
 * PostgreSQL 技能树：https://codechina.csdn.net/csdn/skill_tree_pg
+* Neo4J 技能树：https://codechina.csdn.net/csdn/skill_tree_neo4j
 * OceanBase 技能树：https://codechina.csdn.net/csdn/skill_tree_oceanbase
 * 全栈工具 技能树：https://codechina.csdn.net/csdn/skill_tree_toolchains
 * AI 技能树 https://codechina.csdn.net/csdn/skill_tree_ai