Fix
* fix: Allow benchmark to specify eval_splits (1217)
* fix: Allow benchmark to specify eval_splits
This PR allow for benchmarks to specify specific eval. splits. This allow us to fully specify a benchmark within the benchmark object.
To do this it add the following:
- added eval_splits to the Abstask object, which default to metadata.eval_splits
- use the task.eval_splits unless overwritten in mteb.MTEB.run
- added eval_splits arg to mteb.get_tasks, which filter the tasks based on splits
- updated documentation
- renamed the &34;Advanced Usage&34; to &34;Usage Documentation&34; to make it more accicible
- added tests where relevant
* Added correction based on feedback ([`00260b5`](https://github.com/embeddings-benchmark/mteb/commit/00260b5497b4c82583be6383d8b22a3fceb64b54))