Fix typo + minor change
Fix typo + minor change

* qualify warning about EBU-TT-D conversion as not a *complete*
reference, rather than not a reference at all. Actually it isn’t bad.
* fix retiming delay json name

bbc/ebu-tt-live-toolkit,bbc/ebu-tt-live-toolkit,ebu/ebu-tt-live-toolkit,ebu/ebu-tt-live-toolkit,bbc/ebu-tt-live-toolkit,ebu/ebu-tt-live-toolkit