chore: update readme

Author: leedom92

packages/tailwindcss-miniprogram-preset/README.md

@@ -30,7 +30,7 @@ module.exports = {
      *  mp: false
      * })
      */
-    mp,
+    mp(),
   ],
   content: [...],
   theme: {

packages/tailwindcss-preset/README.md

@@ -30,7 +30,7 @@ module.exports = {
      * 
      * preset({ mp: true })
      */
-    preset,
+    preset(),
   ],
   content: [...],
   theme: {