Update README with most up to date asset list. (#70)

* Update README with most up to date asset list.

* further update

* address comments

Author: dssei

README.md

@@ -1 +1,7 @@
-# registry
+# registry
+
+## Asset list
+Please note, that the [assetlist.json](./assetlist.json) is being deprecated.
+
+Please use [this repo](https://github.com/Sei-Public-Goods/sei-assetlist) to get the latest asset list.
+This asset list is run by community and is not maintained by Sei Labs team.