Enhanced Firewall Restrictions docs

Squashed commits:
[2081fc4] Enhanced Firewall Restrictions docs for PR symfony/symfony#10404
[8f065bc] Add redirect to new page
[b42e80f] fixed typos
[cc6b07d] tiny update
feature #3681 Enhanced Firewall Restrictions docs (danez)

This PR was merged into the master branch.

Discussion
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Enhanced Firewall Restrictions docs

see symfony/symfony#10404

And as I'm not native english, someone please read my changes :)

Commits
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eafbab1 Enhanced Firewall Restrictions docs