Add collection period and usage instructions to dataset card

README.md

@@ -53,14 +53,24 @@ This dataset is the index for a project to build a complete text corpus of Magic
 
 ## Dataset structure
 
-The dataset is a single CSV file, `links.csv`, with one column:
+The dataset is a single CSV file, `links.csv`, with the following columns:
 
 - `url`: The full URL found in the Internet Archive CDX index.
+- `site`: The identifier for the source website (e.g., `mtggoldfish`, `edhrec_articles`).
+- `http_code`: The HTTP status code returned by the Wayback Machine for that URL.
 
 ## Collection method
 
 URLs were pulled using the Internet Archive CDX API. The crawler targeted specific domains known to host Magic: The Gathering content, searching for all unique URLs indexed by the Wayback Machine.
 
+This specific snapshot covers URLs indexed between **2025 and 2026**.
+
+To replicate the discovery process, use the provided `fetch.py` script:
+
+```bash
+python fetch.py discover --from-year 2025 --to-year 2026
+```
+
 ## License
 
 The list of URLs is provided under the Open Data Commons Attribution License (ODC-By). You must follow the terms of service and robots.txt of the source websites if you use these links to download content.