fix types

packages/extension-subscript/src/subscript.ts

@@ -1,24 +1,24 @@
-import { Command, Mark, mergeAttributes } from '@tiptap/core'
+import { Mark, mergeAttributes } from '@tiptap/core'
 
 export interface SubscriptExtensionOptions {
   HTMLAttributes: Object,
 }
 
 declare module '@tiptap/core' {
-  interface Commands {
+  interface Commands<ReturnType> {
     subscript: {
       /**
        * Set a subscript mark
        */
-      setSubscript: () => Command,
+      setSubscript: () => ReturnType,
       /**
        * Toggle a subscript mark
        */
-      toggleSubscript: () => Command,
+      toggleSubscript: () => ReturnType,
       /**
        * Unset a subscript mark
        */
-      unsetSubscript: () => Command,
+      unsetSubscript: () => ReturnType,
     }
   }
 }