feat (docs): grammar

Signed-off-by: Katrin Mehl <katrin.mehl@parson-europe.com>

Author: paagkame

osi_trafficupdate.proto

@@ -10,7 +10,7 @@ package osi3;
 
 //
 // \brief The traffic update message is provided by traffic
-// participant models to provide updates to their position, state
+// participant models to provide updates to their position, state,
 // and future trajectory back to the simulation environment.
 //
 // \note For reasons of convenience and consistency, the