docs: fix duration format in examples

[embano1]

Closes: #253

Issue #, if available:

Description of changes:

Update all examples and imports.

@yaythomas just not sure if we also need to fix

aws-durable-execution-sdk-python/tests/types_test.py

Lines 87 to 89 in f835016

	# Test wait method
	mock_context.wait(10, name="test_wait")
	mock_context.wait.assert_called_once_with(10, name="test_wait")

and why it's working?

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[yaythomas]

and why it's working?

Python type checking is at design time, not run-time, so it won't fail at runtime.

the reason mypy doesn't complain at design time, is because it's a Mock, not the actual object, and Mocks are very permissive with Any type. To test this, we'd have to add a concrete class that implements the DurableContext protocol rather than a mock.

these tests focus on testing that the method exist on the protocol - i.e that the Protocol defines a wait method with the expected parameter names.