Add a simple example with how to use the mock server container

[worldtiki]

No description provided.

[rnorth]

Thanks @worldtiki - that's a good idea.

We are trying to gradually move all code snippets into executable test code that gets included at docs build-time. This means that we can have more confidence that code snippets are correct and up to date.

Could you perhaps have a go at it? We have the process roughly documented here, and there are a few examples of documentation pages that have already been migrated to this approach (e.g. this.

[worldtiki]

Of course :)

[rnorth]

Excellent, thank you :)