Add citation guide to documentation

[Jojogap]

Most frameworks provide some information about how to properly cite the framework. I could not find such a page in the documentation or here in the repo github. As the devlopers published a few papers about stonesoup it would be great to know how to cite their amazing work properly. Thanks!

[sdhiscocks]

We have a Zenodo link in the readme which links back to latest software release, but the latest paper we had announcing v1.0 release is DOI 10.23919/FUSION52260.2023.10224185

We should look to add something to the documentation and also a citation file to the repo, which will generate a citation text/link within GitHub.