Update article.md

Added 'Oxford comma" (comma before 'and' at the end of a list). Not all consider it necessary, but I think it improves readability.

Author: paroche

1-js/10-error-handling/1-try-catch/article.md

@@ -1,6 +1,6 @@
 # Error handling, "try..catch"
 
-No matter how great we are at programming, sometimes our scripts have errors. They may occur because of our mistakes, an unexpected user input, an erroneous server response and for a thousand other reasons.
+No matter how great we are at programming, sometimes our scripts have errors. They may occur because of our mistakes, an unexpected user input, an erroneous server response, and for a thousand other reasons.
 
 Usually, a script "dies" (immediately stops) in case of an error, printing it to console.