minor #3896 Update index.rst (ThomasLandauer)
minor #3896 Update index.rst (ThomasLandauer)

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

Discussion
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Update index.rst

Mentioning "nullable" requirement, since entities created with Maker Bundle doesn't fulfill this by default. Closes https://github.com/EasyCorp/EasyAdminBundle/issues/3889

Commits
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43e3f385 Update index.rst

javiereguiluz/EasyAdminBundle,javiereguiluz/EasyAdminBundle