Add upgrade consideration note for third-party packages implementing their own panels
Add upgrade consideration note for third-party packages implementing their own panels

rsalmaso/wagtail,zerolab/wagtail,thenewguy/wagtail,zerolab/wagtail,wagtail/wagtail,thenewguy/wagtail,thenewguy/wagtail,zerolab/wagtail,thenewguy/wagtail,rsalmaso/wagtail,zerolab/wagtail,zerolab/wagtail,rsalmaso/wagtail,rsalmaso/wagtail,wagtail/wagtail,thenewguy/wagtail,rsalmaso/wagtail,wagtail/wagtail,wagtail/wagtail,wagtail/wagtail