Doc suggestion - IntelliJ Clarity

[benwilcock]

Great tutorial, but I have a few suggestions...

May I suggest that under the chat-getting-started/README.md in note 2, where it mentions using the http files in IntelliJ IDEA, we clarify that this feature is only available in IntelliJ IDEA Ultimate edition. This will prevent IntelliJ Community users from searching for a feature that might not be available to them.

Also, I think it might help folks ease into the exercises if the very first bit of code they need to complete for the first test is suggested to them in the README so it can be copied and pasted and they can get a feel for how the exercise works.

Great job though - highly informative!