Add docs on waiting for signals

[coretl]

Include this use case:

I want to use ophyd_async.core.set_and_wait_for_other_value() to write to a setpoint of a temperature controller and wait until the temperature reaches that value. I am worried that because they're both floats and because temperature is analog that they will never EXACTLY equal to each other and this function may not return when I want it to. How should I handle float precision here?
2 replies
Tom Cobb (DLS)
15 minutes ago

In main, you can pass a callable as match_value to the function, so you could pass lambda v: np.isclose(v, 32.567) to that
12m ago

Or you could pass pytest.approx(32.567) to it

Acceptance Criteria

• Docs tell you how to wait for a signal to be at a value to within a tolerance