minor #3356 [Doc] Built-in action permission method fix + typo (thomas-l)
minor #3356 [Doc] Built-in action permission method fix + typo (thomas-l)

This PR was merged into the 3.0.x-dev branch.

Discussion
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[Doc] Built-in action permission method fix + typo

`->setPermission()` is not available for `Action`, and there is a more simpler method available.

Commits
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1cb29429 Built-in action permission method fix + typo

javiereguiluz/EasyAdminBundle,javiereguiluz/EasyAdminBundle