Add local Selenium Grid setup and configuration guide (#379)

* Initial plan

* Add comprehensive local Selenium Grid execution guide

Co-authored-by: MohabMohie <19201898+MohabMohie@users.noreply.github.com>

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Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: MohabMohie <19201898+MohabMohie@users.noreply.github.com>
Co-authored-by: Mohab Mohie <Mohab.MohieElDeen@outlook.com>

Author: Copilot