use snakecase for action parameter names

Author: ptzianos

action.yml

@@ -6,14 +6,14 @@ inputs:
   directory:
     description: 'Path (relative to repo root) to the Terraform/OpenTofu recipe'
     required: true
-  recipe-nickname:
+  recipe_nickname:
     description: 'Nickname for this recipe that you set on the platform'
     required: true
   host:
     description: 'Base URL of the platform host (used as OIDC audience and upload target)'
     required: false
     default: 'https://infra-app-916613094271.europe-west1.run.app'
-  gcp-credentials-json:
+  gcp_credentials_json:
     description: 'GCP service account JSON credentials for authenticating with Google Cloud Provider'
     required: false