chore: Update package.json license information (#291)

Since the license file is MIT, let's update the package.json to adhere to it.

Author: antoniopaisfernandes

package.json

@@ -81,7 +81,7 @@
     "vue",
     "tooltip"
   ],
-  "license": "ISC",
+  "license": "MIT",
   "repository": {
     "type": "git",
     "url": "git+https://github.com/Akryum/vue-tooltip.git"