message: docs(vue): Document supported version range
diff: This package is a wrapper around `@sentry/browser`, with added functionality related to Vue.js. All methods available in
  `@sentry/browser` can be imported from `@sentry/vue`.
  +It targets Vue version `2.x`. Support for `3.x` is tracked by [GitHub issue #2925](https://github.com/getsentry/sentry-javascript/issues/2925).
  +
  To use this SDK, call `Sentry.init(options)` before you create a new Vue instance.
  ```javascript
  