init from https://github.com/Hufe921/canvas-editor

docs/guide/plugin-custom.md

@@ -0,0 +1,25 @@
+# 自定义插件
+
+::: tip
+官方维护插件仓库：https://github.com/Hufe921/canvas-editor-plugin
+:::
+
+## 开发插件
+
+```javascript
+export function myPlugin(editor: Editor, options?: Option) {
+  // 1. 修改方法，详见：src/plugins/copy
+  editor.command.updateFunction = () => {}
+
+  // 2. 增加方法，详见：src/plugins/markdown
+  editor.command.addFunction = () => {}
+
+  // 3. 事件监听、快捷键、右键菜单、重写方法等组合处理
+}
+```
+
+## 使用插件
+
+```javascript
+instance.use(myPlugin, options?: Option)
+```