docs(*): add acknowledgment to runn project

Probitas is heavily influenced by runn's pioneering work in scenario-based
testing. This acknowledgment expresses our gratitude and respect for the
runn project, while making the lineage of ideas explicit to readers.

Key concepts inherited from runn include ctx.previous for accessing prior
step results, integration of service clients beyond traditional e2e scope,
and the scenario-based execution model itself.

Author: lambdalisue

README.md

@@ -603,6 +603,20 @@ Interested in contributing or maintaining Probitas? See
 - Architecture overview
 - Related repositories
 
+## Acknowledgments
+
+Probitas is greatly inspired by [runn](https://github.com/k1LoW/runn), an
+excellent scenario-based testing tool. Many core concepts in Probitas, such as:
+
+- Accessing previous step results via `ctx.previous`
+- Integration of database clients and other service helpers beyond traditional
+  e2e testing scope
+- Scenario-based workflow execution model
+
+are influenced by runn's thoughtful design. We express our deep gratitude and
+respect to the runn project and its maintainers for pioneering this approach to
+scenario-based testing.
+
 ## License
 
 See [LICENSE](LICENSE) file for details.