sponsorship: Update README.md

Update to our current featured sponsors. Thank you to all our sponsors, past and present 🥰

Author: jemgillam

README.md

@@ -28,7 +28,8 @@ And please give some love to our featured sponsors 🤩:
 
 <table><tr>
 <td align="center"><a href="http://chads.website/"><img src="https://www.graphile.org/images/sponsors/chadf.png" width="90" height="90" alt="Chad Furman" /><br />Chad Furman</a></td>
-<td align="center"><a href="https://timescale.com/"><img src="https://www.graphile.org/images/sponsors/timescale.svg" width="90" height="90" alt="Timescale" /><br />Timescale</a></td>
+<td align="center"><a href="https://storyscript.io/?utm_source=postgraphile"><img src="https://www.graphile.org/images/sponsors/storyscript.png" width="90" height="90" alt="Storyscript" /><br />Storyscript</a></td>
+<td align="center"><a href="http://p72.vc/"><img src="https://www.graphile.org/images/sponsors/p72.png" width="90" height="90" alt="Point72 Ventures" /><br />Point72 Ventures</a></td>
 </tr></table>
 
 <!-- SPONSORS_END -->