新增mvvm示例

Author: esengine

.gitmodules

@@ -22,3 +22,6 @@
 [submodule "thirdparty/mvvm-ui-framework"]
 	path = thirdparty/mvvm-ui-framework
 	url = https://github.com/esengine/mvvm-ui-framework.git
+[submodule "thirdparty/cocos-nexus"]
+	path = thirdparty/cocos-nexus
+	url = https://github.com/esengine/cocos-nexus.git

extensions/cocos/cocos-ecs/assets/resources/prefabs.meta

@@ -0,0 +1,9 @@
+{
+  "ver": "1.2.0",
+  "importer": "directory",
+  "imported": true,
+  "uuid": "2bf3ded8-4054-4d8f-a367-c76b21eaf538",
+  "files": [],
+  "subMetas": {},
+  "userData": {}
+}