Documentation improvement: schemaRegistry parameter when writing DgsTypeDefinitionRegistry

[DarthCoder117]

Just a minor documentation improvement suggestion, but it would be nice to mention on the Dyanic Schemas page that the schemaRegistry parameter can be used to retrieve the current schema when writing a DgsTypeDefinitionRegistry.

https://netflix.github.io/dgs/advanced/dynamic-schemas/

Currently the function is defined like this:

@DgsTypeDefinitionRegistry
public TypeDefinitionRegistry registry() {
    // ...
}

I spent quite a bit of time searching for a way to read what's in the existing schema, and I finally realized I should check how the Relay pagination handles things. That's where I found that the function signature can actually take a TypeDefinitionRegistry like this:

@DgsTypeDefinitionRegistry
public TypeDefinitionRegistry registry(TypeDefinitionRegistry registry) {
    // ...
}

I also noticed when searching for discussions that I'm not the only one that had been looking for the same information:
#1126

[srinivasankavitha]

Thanks for opening this issue. We will fix our docs to reflect this.

[srinivasankavitha]

Addressed and merged: Netflix/dgs#157