docs: add dataset card front-matter, OA license note, and JSONL example

- Set language, tags, task_categories, and size_categories
- Add OA-only license notice (multiple upstream licenses)
- Provide JSONL record schema and example
- Prepare for MLM (DAPT/TAPT) usage

README.md

@@ -1,5 +1,49 @@
----
-license: other
-license_name: multiple
-license_link: LICENSE
----
+---
+language:
+- en
+license: other
+pretty_name: "BIOBERT — Microbiology OA Full-Text Corpus"
+dataset_type: text
+task_categories:
+- fill-mask
+tags:
+- microbiology
+- open-access
+- pmc
+- europe-pmc
+- fulltext
+- mlm
+- pretraining
+- biobert
+- english
+size_categories:
+- unknown
+---
+
+# BIOBERT — Microbiology OA Full-Text Corpus
+
+**Purpose:** Provide an English **Open-Access–only** full-text corpus in microbiology and related domains for:
+- Domain/Task-Adaptive Pretraining (DAPT/TAPT) with **Masked Language Modeling (MLM)**
+- Fine-tuning BERT-style models such as BioBERT
+
+> ⚠️ **Copyright / License:** This repository includes **OA items only** (e.g., PMC / Europe PMC OA). Each item must be used under its **original upstream license**. The fields `license_type` and `license_url` are included in every record. This repository does **not** grant a new license for redistribution.
+
+## Data format
+Recommended file format: **JSON Lines (`.jsonl`)** — one document/section per line.
+
+**Example record**
+```json
+{
+  "id": "pmcid:PMC1234567#sec3",
+  "title": "Sample article title",
+  "text": "full body text …",
+  "source": "PMC",
+  "pmcid": "PMC1234567",
+  "doi": "10.xxxx/xxxx",
+  "year": 2024,
+  "journal": "Journal Name",
+  "section": "body",
+  "license_type": "CC-BY-4.0",
+  "license_url": "https://creativecommons.org/licenses/by/4.0/",
+  "url": "https://europepmc.org/…"
+}