add historyPluginOptions

packages/core/src/Extension.ts

@@ -4,14 +4,13 @@ export default abstract class Extension {
 
   constructor(options = {}) {
     this.options = {
-      ...this.defaultOptions,
+      ...this.defaultOptions(),
       ...options,
     }
   }
   
   editor!: Editor
   options: { [key: string]: any } = {}
-  defaultOptions: { [key: string]: any } = {}
   
   public abstract name: string
   
@@ -23,6 +22,10 @@ export default abstract class Extension {
     this.editor = editor
   }
 
+  defaultOptions(): { [key: string]: any } {
+    return {}
+  }
+
   update(): any {
     return () => {}
   }