documentation for integrations

**Describe the proposed change**

There's a growing number of integrations. Most recently Datamaestro (see #99)! We should document them, give a little promotion for each one, and provide instructions and/or code samples on how to use it in each tool. Similar to what's in the paper, but more detailed and accessible. Probably both in the README and have a dedicated documentation page for them? (Or a dedicated documentation page for each one?)

So far, these are the ones I'm aware of:
- [ ] [Datamaestro](https://github.com/experimaestro/datamaestro)
- [x] [PyTerrier](https://github.com/terrier-org/pyterrier)
- [ ] [Capreolus](https://github.com/capreolus-ir/capreolus)
- [ ] [OpenNIR](https://github.com/Georgetown-IR-Lab/OpenNIR)
- [ ] [DiffIR](https://github.com/capreolus-ir/diffir)
- [ ] [Anserini](https://github.com/castorini/anserini) (and maybe pyserini?)
- [x] [ir_measures](https://ir-measur.es/en/latest/)