Update README with project description and links

Author: tianzhou

README.md

@@ -1,4 +1,6 @@
 > [!NOTE]
+> pgplex: The Postgres Toolchain for Humans and Agents - **pgconsole** · [pgschema](https://github.com/pgplex/pgschema) · [pgtui](https://github.com/pgplex/pgtui) · [pgparser](https://github.com/pgplex/pgparser)
+> 
 > Brought to you by [Bytebase](https://www.bytebase.com/), open-source database DevSecOps platform.
 
 ![](https://raw.githubusercontent.com/pgplex/website/refs/heads/main/public/banner-pgconsole.png)