Merge pull request #231 from Goziee-git/feature/openverse-docs

Add Openverse API source to documentation in `sources.md`

Author: TimidRobot

sources.md

@@ -121,6 +121,32 @@ and access towards related query data using a programmable search engine.
 - Data available through JSON format
 
 
+## Openverse
+
+**Description:** Openverse is a search engine for openly licensed media,
+including images and audio. It provides access to over 700 million works from
+more than 20 sources, all of which are under Creative Commons licenses or in the
+public domain. The API allows querying for media by source, license type, and
+other parameters. Because anonymous Openverse API access returns a maximum of
+~240 result count per source-license combination, the `openverse_fetch.py`
+script currently provides approximate counts. It does not include pagination or
+license_version breakdown.
+
+**API documentation link:**
+- [Openverse API Documentation](https://api.openverse.org/v1/)
+- [Openverse API Reference](https://wordpress.org/openverse/api/)
+- [Base URL](https://api.openverse.org/v1)
+- [Openverse Frontend](https://openverse.org/)
+
+**API information:**
+- No API key required for basic access
+- Query limit: Rate-limited to prevent abuse (anonymous access provides ~240 results per source-license combination)
+- Data available through JSON format
+- Supports filtering by source, license, media type (images, audio)
+- Media types: `images`, `audio`
+- Supported licenses: `by`, `by-nc`, `by-nc-nd`, `by-nc-sa`, `by-nd`, `by-sa`, `cc0`, `nc-sampling+`, `pdm`, `sampling+`
+
+
 ## Wikipedia
 
 **Description:** The Wikipedia API allows users to query statistics of pages,