[doc] Update Codegen doc to use Server Preset

Hello 👋
I'm from [The Guild](https://the-guild.dev/) and I want to propose updating the [Generating TS types](https://www.apollographql.com/docs/apollo-server/workflow/generate-types) to use the [Server Preset](https://the-guild.dev/graphql/codegen/docs/guides/graphql-server-apollo-yoga-with-server-preset) instead of the current setup.

This is now our recommended way to write server code, and I believe it gives users much better DevX:
- has automatic type wireup for better type-safety
- results in less runtime errors
- easier typeDefs and resolvers setup

I'm thinking to keep the similar flow to the current doc and only update relevant bits to keep it short. Happy to chat more! 🙂

Start with the Generating TS types page linked in the issue and compare its current setup with the Server Preset guide. Update the relevant parts while keeping the existing flow concise, and confirm that the page consistently presents Server Preset as the recommended approach.

Written by the indexing model from the issue text.