TYPO3 8.7: Remove <div> tag around content elements

In your PageTSConfig add the following:

#no frame around content elements
TCAdefaults.tt_content.frame_class = none

All new content elements will get the "frame class" set to none, which disables the frame in `typo3_src/typo3/sysext/fluid_styled_content/Resources/Private/Layouts/Default.html.