update news tmb

Author: joethorley

NEWS.md

@@ -156,6 +156,7 @@ ssdtools version 1.0.0 is the first major release of `ssdtools` with some import
 ## Fitting
 
 An important change to the functionality of `ssd_fit_dists()` was to switch from model fitting using [`fitdistrplus`](https://github.com/lbbe-software/fitdistrplus) to [`TMB`](https://github.com/kaskr/adcomp) to allow full control over model specification as well as improved handling of censored data.
+The change is internal and does not affect the user interface.
 Although it was hoped that model fitting would be faster this is currently not the case.
 
 As a result of the change the `fitdists` objects returned by `ssd_fit_dists()` from previous versions of `ssdtools` are not compatible with the major release and should be regenerated.