chore(sponsor): add Jspreadsheet (fastify#5971)

Author: Eomm

SPONSORS.md

@@ -13,10 +13,11 @@ _Be the first!_
 
 ## Tier 3
 
-- [Handsontable - JavaScript Data Grid](https://handsontable.com/docs/react-data-grid/?utm_source=Fastify_GH&utm_medium=sponsorship&utm_campaign=library_sponsorship_2024)
-- [Lokalise - A Localization and Translation Software Tool](https://lokalise.com/?utm_source=Fastify_GH&utm_medium=sponsorship)
 - [Mercedes-Benz Group](https://github.com/mercedes-benz)
 - [Val Town, Inc.](https://opencollective.com/valtown)
+- [Handsontable - JavaScript Data Grid](https://handsontable.com/docs/react-data-grid/?utm_source=Fastify_GH&utm_medium=sponsorship&utm_campaign=library_sponsorship_2024)
+- [Jspreadsheet](https://jspreadsheet.com/)
+- [Lokalise - A Localization and Translation Software Tool](https://lokalise.com/?utm_source=Fastify_GH&utm_medium=sponsorship)
 
 ## Tier 2