doc: add more cmd in unit test documentation (#1963)

tests/unit/README.md

@@ -1,7 +1,23 @@
 ## Introduction
 
-This folder contains unit tests that could be run locally by
+This folder contains unit tests that could be run locally.
+
+Run all test:
 
 ```bash
 poetry run pytest ./tests/unit
 ```
+
+Run specific test file:
+
+```bash
+poetry run pytest ./tests/unit/test_micro_agents.py
+```
+
+Run specific unit test
+
+```bash
+poetry run pytest ./tests/unit/test_micro_agents.py:test_coder_agent_with_summary
+```
+
+More details see [pytest doc](https://docs.pytest.org/en/latest/contents.html)