Client connection docs improvement

[devbugging]

We should extend our docs to cover different options when connecting with the client:

• Option to connect using secure connection
• Option to connect using the retries as stated bellow:

opts := []grpc_retry.CallOption{
  grpc_retry.WithBackoff(grpc_retry.BackoffExponential(100 * time.Millisecond)),
}

c, err := client.New(
  "access.mainnet.nodes.onflow.org:9000",
  grpc.WithUnaryInterceptor(grpc_retry.UnaryClientInterceptor(opts...)),
)