Add Etherspot's tutorials to External Learning Resources

docs/dev/external-resources.md

@@ -6,8 +6,10 @@ Curated list of resources you can use to extend your knowledge of the Flare netw
 
 * [Filip Koprivec's Flare Tutorials on Medium](https://j0-0sko.medium.com/flare-blogposts-toc-8dc9d862f743)
 * [Uttam Singh's Using the Flare Time Series Oracle with Foundry](https://medium.com/flarenetwork/using-the-flare-time-series-oracle-with-foundry-a726afc993c1)
+* [Etherspot Prime on Flare](https://etherspot.fyi/getting-started-on-flare)
 
 ## Videos
 
 * [Tim Rowley's Explainer Videos on YouTube](https://www.youtube.com/@timothyrowley/videos)
 * [FTSO (Flare Time Series Oracle) | Learn how to Query Prices on Flare](https://youtu.be/tSODrEVA3BI)
+* [Introduction to Etherspot's TransactionKit on Flare](https://www.youtube.com/watch?v=80Ycm-nYBwg)