minor #3945 Add note on callable signature (tarjei)
minor #3945 Add note on callable signature (tarjei)

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

Discussion
----------

Add note on callable signature

<!--
Thanks for your contribution! If you are proposing a new feature that is complex,
please open an issue first so we can discuss about it.

Note: all your contributions adhere implicitly to the MIT license
-->

Commits
-------

97f5e28b Add note on callable signature

javiereguiluz/EasyAdminBundle,javiereguiluz/EasyAdminBundle