docs: add README

README.md

@@ -1,4 +1,25 @@
 ---
+pretty_name: ECHR Retrieval
+task_categories:
+- text-retrieval
+- summarization
+- text-ranking
+tags:
+- legal
+- law
+- judicial
+- eu
+source_datasets:
+- HUDOC
+language:
+- en
+annotations_creators:
+- found
+language_creators:
+- found
+license: cc-by-4.0
+size_categories:
+- n<1K
 dataset_info:
 - config_name: default
   features:
@@ -44,4 +65,40 @@ configs:
   data_files:
   - split: queries
     path: queries.jsonl
----
+---
+
+# ECHR Retrieval 🏛️
+**ECHR Retrieval** by [Isaacus](https://isaacus.com/) is a challenging legal information retrieval evaluation dataset consisting of 200 short summaries of findings of European Court of Human Rights decisions paired with the text of those decisions sourced from the [HUDOC](https://hudoc.echr.coe.int/) database.
+
+This dataset is intended to stress test the ability of an information retrieval model to retrieve relevant court decisions given arbitrary legal holdings.
+
+This dataset forms part of the [Massive Legal Embeddings Benchmark (MLEB)](https://isaacus.com/mleb), the largest, most diverse, and most comprehensive benchmark for legal text embedding models. ECHR Retrieval was added to MLEB on 20 February 2026.
+
+## Structure 🗂️
+As per the MTEB information retrieval dataset format, this dataset comprises three splits, `default`, `corpus` and `queries`.
+
+The `default` split pairs summaries (`query-id`) with decisions (`corpus-id`), each pair having a `score` of 1.
+
+The `corpus` split contains European Court of Human Rights decisions, with the text of decisions being stored in the `text` key and their ids being stored in the `_id` key. There is also a `title` column which is deliberately set to an empty string in all cases for compatibility with the [`mteb`](https://github.com/embeddings-benchmark/mteb) library.
+
+The `queries` split contains summaries of the findings of decisions, with the text of summaries being stored in the `text` key and their ids being stored in the `_id` key.
+
+## Methodology 🧪
+This dataset was constructed by collecting all publicly available European Court of Human Rights decisions, cleaning them, and then sampling 200 summary-decision pairs for inclusion in this dataset.
+
+## License 📜
+This dataset is licensed under [CC BY 4.0](https://choosealicense.com/licenses/cc-by-4.0/) which allows for both non-commercial and commercial use of this dataset as long as appropriate attribution is made to it.
+
+## Citation 🔖
+If you use this dataset, please cite the [Massive Legal Embeddings Benchmark (MLEB)](https://arxiv.org/abs/2510.19365):
+```bibtex
+@misc{butler2025massivelegalembeddingbenchmark,
+      title={The Massive Legal Embedding Benchmark (MLEB)}, 
+      author={Umar Butler and Abdur-Rahman Butler and Adrian Lucas Malec},
+      year={2025},
+      eprint={2510.19365},
+      archivePrefix={arXiv},
+      primaryClass={cs.CL},
+      url={https://arxiv.org/abs/2510.19365}, 
+}
+```