chore: workflow endpoints (#13)

Author: notnmeyer

README.md

@@ -64,6 +64,7 @@ client := loops.NewClient("YOUR_API_KEY",
 - Components — `GetComponent`, `ListComponents`
 - Themes — `GetTheme`, `ListThemes`
 - Uploads — `Upload`, `CreateUpload`, `CompleteUpload`
+- Workflows — `ListWorkflows`, `GetWorkflow`, `GetWorkflowNode`
 
 Full reference: [pkg.go.dev/github.com/loops-so/loops-go](https://pkg.go.dev/github.com/loops-so/loops-go).