Document loss of Simulate et al

Author: japgolly

doc/changelog/3.0.0.md

@@ -107,3 +107,34 @@ find . -type f -name '*.scala' -exec perl -pi -e '
   s/\bReactTestUtils2\b/ReactTestUtils/g;
 ' {} +
 ```
+
+### `Simulate`, `SimEvent`, `Simulation`
+
+React has removed `Simulate` as of React v19. It is deprecated in React v18.
+
+React now recommends using [React Testing Library](https://testing-library.com/react) instead.
+There is no Scala.js facade for it, and even if there was it wouldn't be a drop-in replacement.
+
+As a band-aid solution, there is now a new scalajs-react module called `testing_library-dom`
+that builds on `@testing-library/dom` and
+provides a subset of `Simulate`, `SimEvent`, `Simulation` under the
+`japgolly.scalajs.react.testing_library.dom` package.
+
+Unfortunately some types of events like `Simulate.change` do not fire and thus have been removed from the API.
+
+Add this to your sbt:
+
+```scala
+libraryDependencies += "com.github.japgolly.scalajs-react" %%% "testing_library-dom" % "3.0.0" % Test
+
+jsDependencies += "org.webjars.npm" % "testing-library__dom" % "10.4.1" /
+                    "dom.umd.js" commonJSName "TestingLibraryDom" % Test
+```
+
+and to use it:
+
+```scala
+import japgolly.scalajs.react.testing_library.dom.Simulate
+
+// Simulate.click(domNode)
+```