Update README.md

Author: miccol

README.md

@@ -90,15 +90,15 @@ The repository [my-behavior-tree-project](https://github.com/miccol/my-behavior-
 
 CREATE YOUR OWN ACTION NODE
 ------
-1) Implement your action node class inheriting the abstract class`BT::ActionNode`.
+1) Implement your action node class extending 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 gets preempted (halted).
 See the file `src/example.cpp` for an example.
 
 CREATE YOUR OWN CONDITION NODE
 ------
-1) Implement your condition node class inheriting the abstract class`BT::ConditionNode`.
-2) Implement the method `Tick()` with the code you want to execute to check the condition. Return `BT::SUCCESS` or `BT::FAILURE` accordingly.  
+1) Implement your condition node class extending the abstract class `BT::ConditionNode`.
+2) Implement the method `BT::ReturnStatus Tick()` with the code you want to execute to check the condition. Return `BT::SUCCESS` or `BT::FAILURE` accordingly.  
 See the file `src/example.cpp` for an example.
 
 LICENSE