fix conflict in lists-and-keys.md

Author: balazsorban44

content/docs/lists-and-keys.md

@@ -184,14 +184,8 @@ function ListItem(props) {
 function NumberList(props) {
   const numbers = props.numbers;
   const listItems = numbers.map((number) =>
-<<<<<<< HEAD
     // Helyes! A kulcsot itt kell definiálni:
-    <ListItem key={number.toString()}
-              value={number} />
-=======
-    // Correct! Key should be specified inside the array.
     <ListItem key={number.toString()} value={number} />
->>>>>>> b4b59062e59d56da37274c6de1fa4a134d2d8f49
   );
   return (
     <ul>