Align README install command with python3 invocation

Co-authored-by: Shri Sukhani <shrisukhani@users.noreply.github.com>

Author: cursoragent

README.md

@@ -232,7 +232,7 @@ except HyperbrowserTimeoutError:
 ## Development
 
 ```bash
-pip install -e . pytest ruff build
+python3 -m pip install -e . pytest ruff build
 python3 -m ruff check .
 python3 -m ruff format --check .
 python3 -m pytest -q

tests/test_docs_python3_commands.py

@@ -12,6 +12,8 @@ def test_readme_and_contributing_use_python3_commands():
 
     assert "python -m" not in readme_text
     assert "python -m" not in contributing_text
+    assert not re.search(r"^\s*pip install -e \. pytest ruff build\s*$", readme_text, re.MULTILINE)
+    assert "python3 -m pip install -e . pytest ruff build" in readme_text
 
 
 def test_example_run_blocks_use_python3():