executors/ramping-arrival-rate | incorrect number of performed iterations in the example

[gera-cl]

The number of the performed iterations specified for the example is incorrect (4020), the correct number is 4260.
I calculated the number of each stage using the following equation: duration * (initial rate + target rate) / 2 and then added all the stages. To confirm, I ran the example script getting the same result.

Docs feedback: /docs/sources/v0.50.x/using-k6/scenarios/executors/ramping-arrival-rate.md
URL: https://grafana.com/docs/k6/latest/using-k6/scenarios/executors/ramping-arrival-rate/#observations