Adding a link to example usage in nimble documentation to README

[matt-graham]

Raising as part of JOSS review openjournals/joss-reviews/issues/6745

After a bit of searching I was able to find an example of using nimbleHMC in the main nimble user manual. While the line

nimbleHMC/README.md

Line 10 in 41c782e

See the [nimble website](https://r-nimble.org/) for more information and examples.

does provide a general pointer to the nimble website (and so user manual), it would be good to have a specific link to the example nimbleHMC usage somewhere to aid users wanting to get started with using nimbleHMC, or including a self-contained example in the README (though appreciate you might not want to have the resulting repetition / need to keep the examples in two places in sync with API changes).

[danielturek]

@matt-graham Great comment. This is addressed in PR #52.

I opted for adding a link to the user manual, so that we can avoid maintaining examples in multiple different places.

[danielturek]

@matt-graham PR #52 has been merged.

I'll leave it to you to review, and close this issue if you agree it's been addressed.

[matt-graham]

Thanks looks good to me!