docs(starship-action): add README.md

.github/actions/starship-action/README.md

@@ -0,0 +1,13 @@
+# Starship Devnet Action (Agoric fork)
+
+This `starship-action` was extracted from https://github.com/hyperweb-io/starship-action/tree/0.3.0
+
+We took:
+- action.yaml
+- install.sh
+- port-forward.sh
+
+Agoric added the `load-docker-images` input parameter to be able to import locally-built Docker images into Starship's Kubernetes cluster.
+
+Also, we ran `yarn prettier --write .github/actions/starship-action` to reformat
+the code to our repository's standards.