Added new database: Fast in-process analytical database with C API.

Introduces a new database, designed for fast, in-process analytical
tasks.
The database provides a C API for seamless integration into existing
projects, offering users a powerful tool for efficient data analysis
within applications.

README.md

@@ -256,6 +256,7 @@ Databases and data stores with C APIs.
 
 * [BerkeleyDB][380] - Library for a high-performance embedded database for
   key-value data. [``AGPL-3.0-only``][AGPL-3.0-only]
+* [DuckDB][702] - Fast in-process analytical database, with C API. [``MIT``][MIT]  
 * [EJDB2][568] - Embeddable JSON Database engine. [``MIT``][MIT]
 * [Groonga][524] - Columnar store with full-text search. [``LGPL-2.1-only``][LGPL-2.1-only]
 * [Hiredis][201] - Minimalistic client library for Redis.
@@ -1835,3 +1836,4 @@ support for C.
 [623]: https://github.com/ashvardanian/StringZilla
 [700]: https://viewsourcecode.org/snaptoken/kilo/
 [701]: https://wiki.gnome.org/Projects/GLib
+[702]: https://duckdb.org/