Docs improvements from @jyu00 and rename Latest updates to Changelog

[abbycross]

Closes #4937
Closes #4938
Closes #4680
Closes #4959

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[qiskit-bot]

One or more of the following people are relevant to this code:

• @blakejohnson
• @jyu00
• @abbycross
• @beckykd
• dtmcclure

[kaelynj]

LGTM! 🚀

[jyu00]

Some minor adjustment because I didn't test the code first 🙈

[jyu00]

We also need to initialize the duration & sum it up in the loop:

# Schedule the circuit to get more accurate timing
pm = generate_preset_pass_manager(
    target=backend.target,
    optimization_level=0,
    scheduling_method="alap"
)

scheduled_circuits = pm.run(isa_circuits)

init_duration = backend.target["reset"][(0,)].duration
rep_delay = sampler.options.execution.rep_delay or backend.default_rep_delay

circuit_duration = 0

for circuit in scheduled_circuits:
    # Estimate circuit length
    circuit_duration += circuit.estimate_duration(backend.target)

    # Add INIT time
    if sampler.options.execution.init_qubits:
        circuit_duration += init_duration

    # Add rep_delay
    circuit_duration += rep_delay

total_time = 2 + (circuit_duration*shots)
print(f"Total estimated usage is {math.ceil(total_time)} seconds")

[abbycross]

@jyu00 there were a couple small discrepancies between the recent code block you shared and the recent commits you suggested, so I chose the code block as the source of truth - lmk if I should have done otherwise :D

[jyu00]

Thanks Abby!