Update NEWS.md

NEWS.md

@@ -11,6 +11,7 @@
 - The interface for defining delay distributions has been generalised to also cater for continuous distributions
 - When defining probability distributions these can now be truncated using the `tolerance` argument
 - Ornstein-Uhlenbeck and 5 / 2 Matérn kernels have been added. By @sbfnk in # and reviewed by @.
+- Switch to broadcasting from random walks and added unit tests. By @seabbs in #747 and reviewed by @jamesmbaazam.
 
 ## Bug fixes
 
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 - Updated the documentation of the dots argument of the `stan_sampling_opts()` to add that the dots are passed to `cmdstanr::sample()`. By @jamesmbaazam in #699 and reviewed by @sbfnk.
 - `generation_time_opts()` has been shortened to `gt_opts()` to make it easier to specify. Calls to both functions are equivalent. By @jamesmbaazam in #698 and reviewed by @seabbs and @sbfnk .
+- Added stan documentation for `update_rt`. By @seabbs in #747 and reviewed by @jamesmbaazam.
 
 # EpiNow2 1.5.2