Site: Fix typo in index.md

Author: strongduanmu

site/_docs/index.md

@@ -182,7 +182,7 @@ highly welcomed!
 * Any Avatica version
 * *Maintainer*: Waylay.io
 
-### Calcite Avatica CLI: A Go-based Toool
+### Calcite Avatica CLI: A Go-based Tool
 * [Home page](https://github.com/satyakommula96/calcite-cli)
 * Language: Go
 * *License*: [Apache 2.0](https://www.apache.org/licenses/LICENSE-2.0)