add basic font-family extension

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

@@ -1,5 +1,12 @@
 <template>
   <div v-if="editor">
+    <button @click="editor.chain().focus().fontFamily('Inter').run()">
+      Inter
+    </button>
+    <button @click="editor.chain().focus().fontFamily('Comic Sans MS').run()">
+      Comic Sans
+    </button>
+
     <editor-content :editor="editor" />
   </div>
 </template>
@@ -12,6 +19,7 @@ import Paragraph from '@tiptap/extension-paragraph'
 import Text from '@tiptap/extension-text'
 import Heading from '@tiptap/extension-heading'
 import TextStyle from '@tiptap/extension-text-style'
+import FontFamily from '@tiptap/extension-font-family'
 
 export default {
   components: {
@@ -32,6 +40,7 @@ export default {
         Text(),
         Heading(),
         TextStyle(),
+        FontFamily(),
       ],
       content: `
         <h2>Hello</h2>