Update concepts/type-checking/about.md

Co-authored-by: Derk-Jan Karrenbeld <[email protected]>

Author: quintuple-mallard

concepts/type-checking/about.md

@@ -119,15 +119,17 @@ const espresso = new Coffee();
 ```
 
 ````exercism/note
-`in` can be slightly unreliable, as it will return `true` for inherited properties and methods.
+`in` will return `true` for inherited properties and methods.
+
 ```javascript
 "coolDown" in espresso
 // => true
 
 "constructor" in espresso
 // => true
 ```
-To avoid this, use the hasOwnProperty() method.
+
+To avoid this, use `Object.hasOwn()` instead
 ````
 
 ## The `Object.hasOwn()` function