docs: Update example to apollo-client v3

[gabo2192]

I'm just updating the list of dependencies that needs to goes into this example using Apollo Client V3 where you only need to install @apollo/client graphql subscriptions-transport-ws ws.

Description

Documentation

Related Issues

[LekoArts]

Thanks!

[delroh]

Was going through the tutorial and ran into issues here. Suggested fixes:

• @apollo-client is invalid tag name. Should be @apollo/client .
• Must add react to npm install along with @apollo/client at line 204 because apollo client v3 requires react . See: Feature: Removing React from the default @apollo/client entry point apollographql/apollo-client#8190 & apollo-client require react ?? apollographql/apollo-client#7318
• The rest of the tutorial wasn't updated to also use version 3 of apollo client. See lines 443 to 452
• The example source code is using apollo client v2. Both the tutorial and the example source code should be using the same version so people have some reference to compare the code they wrote by following the tutorial.