Small bug / typo in example?

Hi all, thanks for this client library! Just a small thing I noticed in the example code snippet, I beleive you want to dereference with a '*', otherwise you'll just get the memory address printed to the console:

```go
fmt.Println(*rst.Candidates[0].Content.Parts[0])
```

instead of 

```go
fmt.Println(rst.Candidates[0].Content.Parts[0])
```

Cheers!