[2.3] Examples that points to the DataCollectorListener should be removed.
Reverted removal, removed API links instead
minor #4237 Finished #3886 (ahsio, WouterJ)

This PR was merged into the 2.3 branch.

Discussion
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Finished #3886

Replaces https://github.com/symfony/symfony-docs/pull/3886

Commits
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01057ae Reverted removal, removed API links instead
0670f25 [2.3] Examples that points to the DataCollectorListener should be removed.