fix: fix a bug when configurating the same extension multiple times

packages/core/src/Extension.ts

@@ -256,7 +256,9 @@ export class Extension<Options = any> {
   configure(options: Partial<Options> = {}) {
     this.options = mergeDeep(this.options, options) as Options
 
-    return this
+    // return a new instance so we can use the same extension
+    // with different calls of `configure`
+    return this.extend()
   }
 
   extend<ExtendedOptions = Options>(extendedConfig: Partial<ExtensionConfig<ExtendedOptions>> = {}) {

packages/core/src/Mark.ts

@@ -353,7 +353,9 @@ export class Mark<Options = any> {
   configure(options: Partial<Options> = {}) {
     this.options = mergeDeep(this.options, options) as Options
 
-    return this
+    // return a new instance so we can use the same extension
+    // with different calls of `configure`
+    return this.extend()
   }
 
   extend<ExtendedOptions = Options>(extendedConfig: Partial<MarkConfig<ExtendedOptions>> = {}) {

packages/core/src/Node.ts

@@ -434,7 +434,9 @@ export class Node<Options = any> {
   configure(options: Partial<Options> = {}) {
     this.options = mergeDeep(this.options, options) as Options
 
-    return this
+    // return a new instance so we can use the same extension
+    // with different calls of `configure`
+    return this.extend()
   }
 
   extend<ExtendedOptions = Options>(extendedConfig: Partial<NodeConfig<ExtendedOptions>> = {}) {