Update src/optimise/train.jl

Co-authored-by: Brian Chen <ToucheSir@users.noreply.github.com>

Author: svilupp

src/optimise/train.jl

@@ -87,7 +87,7 @@ Here `pars` is produced by calling [`Flux.params`](@ref) on your model.
 (Or just on the layers you want to train, like `train!(loss, params(model[1:end-2]), data, opt)`.)
 This is the "implicit" style of parameter handling.
 
-Then, this gradient is used by optimizer `opt` to update the parameters:
+This gradient is then used by optimizer `opt` to update the parameters:
 ```
     update!(opt, pars, grads)
 ```