feat: 发布 DSH 生图插件与中文安装使用文档

vendor/imagegen/agents/openai.yaml

@@ -0,0 +1,6 @@
+interface:
+  display_name: "Image Gen"
+  short_description: "Generate or edit images for websites, games, and more"
+  icon_small: "./assets/imagegen-small.svg"
+  icon_large: "./assets/imagegen.png"
+  default_prompt: "Use $imagegen to make or edit an image for this project."