Update README.md

Author: miccol

README.md

@@ -107,7 +107,7 @@ CREATE YOUR OWN ACTION NODE
 ------
 1) Implement your action node class inheriting the abstract class`BT::ActionNode`.
 2) Implement the method `BT::ReturnStatus Tick()` with the code you want to execute while the action is running. Use the method `is_halted()` to check if the action has been prempted. When the execution of your action finished, return `BT::SUCCESS` or `BT::FAILURE` accordingly.  
-3) Implement the method `void Halt()` with the code you want to execute when the action get preempted (halted).
+3) Implement the method `void Halt()` with the code you want to execute when the action gets preempted (halted).
 See the file `src/example.cpp` for an example.
 
 CREATE YOUR OWN CONDITION NODE