Add config for CLA (#1726)

.clabot

@@ -0,0 +1,4 @@
+{
+  "contributors": "https://cla.tailwind-elements.com/users",
+  "message": "Thank you for your pull request and welcome to our community! We require contributors to sign a [Contributor License Agreement](https://cla.tailwind-elements.com/) and we don't seem to have CLAs on file for these contributors to the Pull Request: ({{usersWithoutCLA}}). In order for your PR to be reviewed and merged, please sign our CLA first.\n\nIf there are any questions, please don't hesitate to [get in touch with our team](https://github.com/mdbootstrap/Tailwind-Elements/discussions)."
+}