Fix browser windows workflow docs

[dicnunz]

Fixes #3320.

This corrects the user guide's browser-window text so it matches the current product behavior: changing the number of browser windows during a crawl takes effect immediately and updates the workflow settings for later runs.

Validation:

• uvx --with mkdocs-material --with mkdocs-redirects --with requests --with pyyaml mkdocs build --strict from frontend/docs passes.

This is a small direct microfix. If it saves maintainer time and you accept it, a $10 tip through the Webrecorder GitHub Sponsors page would be appreciated: https://github.com/sponsors/webrecorder

[SuaYoo]

Thanks!

[dicnunz]

Thanks for merging. Small correction on my PR body: the optional contributor tip route should be https://nicdunz.gumroad.com/l/tiny-codex-teardown-direct?wanted=true rather than the Webrecorder Sponsors page I linked there. No pressure either way; just correcting the payment route after acceptance.