add multicolor option to highlight

docs/src/demos/Marks/Highlight/index.vue

@@ -64,7 +64,7 @@ export default {
         Document,
         Paragraph,
         Text,
-        Highlight,
+        Highlight.configure({ multicolor: true }),
       ],
       content: `
         <p>This isn’t highlighted.</s></p>

docs/src/docPages/api/marks/highlight.md

@@ -13,9 +13,10 @@ yarn add @tiptap/extension-highlight
 ```
 
 ## Settings
-| Option         | Type     | Default | Description                                                           |
-| -------------- | -------- | ------- | --------------------------------------------------------------------- |
-| HTMLAttributes | `Object` | `{}`    | Custom HTML attributes that should be added to the rendered HTML tag. |
+| Option         | Type      | Default | Description                                                           |
+| -------------- | --------- | ------- | --------------------------------------------------------------------- |
+| multicolor     | `Boolean` | `false` | Add support for multiple colors.                                      |
+| HTMLAttributes | `Object`  | `{}`    | Custom HTML attributes that should be added to the rendered HTML tag. |
 
 ## Commands
 | Command         | Options            | Description               |

packages/core/src/Extension.ts

@@ -19,7 +19,7 @@ export interface ExtensionConfig<Options = any, Commands = {}> {
    */
   addGlobalAttributes?: (this: {
     options: Options,
-  }) => GlobalAttributes,
+  }) => GlobalAttributes | {},
 
   /**
    * Commands

packages/core/src/Mark.ts

@@ -60,7 +60,7 @@ export interface MarkConfig<Options = any, Commands = {}> extends Overwrite<Exte
     this: {
       options: Options,
     },
-  ) => Attributes,
+  ) => Attributes | {},
 
   /**
    * Commands

packages/core/src/Node.ts

@@ -95,7 +95,7 @@ export interface NodeConfig<Options = any, Commands = {}> extends Overwrite<Exte
     this: {
       options: Options,
     },
-  ) => Attributes,
+  ) => Attributes | {},
 
   /**
    * Commands

packages/extension-highlight/src/index.ts

@@ -7,6 +7,7 @@ import {
 } from '@tiptap/core'
 
 export interface HighlightOptions {
+  multicolor: boolean,
   HTMLAttributes: {
     [key: string]: any
   },
@@ -19,10 +20,15 @@ const Highlight = Mark.create({
   name: 'highlight',
 
   defaultOptions: <HighlightOptions>{
+    multicolor: false,
     HTMLAttributes: {},
   },
 
   addAttributes() {
+    if (!this.options.multicolor) {
+      return {}
+    }
+
     return {
       color: {
         default: null,