Suggestion in the sample prompts area

In the sample prompts area, https://github.com/foxitsoftware/foxit-pdf-api-mcp-server?tab=readme-ov-file#making-your-first-request, I'd suggest adding a sample that demonstrates providing a result name. So for example:

```
combine foo.pdf and goo.pdf and name it something.pdf
```

I tried that on a whim to see if it works, and it did, but I'd make it more obvious it's supported.