Chore: add a script to export OpenAPI types from the CGW Swagger (#80)

Author: katspaugh

scripts/make-cgw-types.sh

@@ -0,0 +1,5 @@
+#!/bin/bash
+
+mkdir -p openapi
+curl 'https://safe-client.gnosis.io/openapi.json' > openapi/cgw.json
+npx openapi-typescript openapi/cgw.json --output openapi/cgw.ts