update README to use major version

Author: n-g

README.md

@@ -18,7 +18,7 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v3
       - name: Configure access to Namespace
-        uses: namespacelabs/nscloud-setup@v0.0.5
+        uses: namespacelabs/nscloud-setup@v0
       - name: Create an ephemeral cluster
         run: |
           nsc cluster create