Docs should have Firebase SQL Connect instead of Data Connect

[codercatdev]

To use Data Connect features, install the Firebase Data Connect Visual Studio Extension.
Alternatively, you can install the extension from the Visual Studio Code Marketplace or search for it within VS

screenshot should also be updated

https://firebase.google.com/codelabs/firebase-dataconnect-web#1

[codercatdev]

I have PR #35 for updating the repo readme, but most likely it needs a new repo with all of the names that are incorrect throughout.