Add Web‑Types JSON for JetBrains IDEs

[RohiNof]

Currently, Alpine.js does not provide a Web‑Types JSON file for JetBrains IDEs.
Providing an official Web‑Types file would allow IDEs like IntelliJ IDEA to recognize Alpine’s x-* directives (e.g., x-data, x-bind, x-on) and provide features such as autocomplete, in-editor documentation, and validation.

It would be great if Alpine.js could publish a Web‑Types file alongside the framework, similar to how some other libraries provide this for IDE support.