Fix typo in article.md (#993)

Fix typo in article.md

Author: lex111

1-js/06-advanced-functions/06-function-object/article.md

@@ -340,7 +340,7 @@ Functions are objects.
 
 Here we covered their properties:
 
-- `name` -- the function name. Usually taken from the function definition, but if there's non, JavaScript tries to guess it from the context (e.g. an assignment).
+- `name` -- the function name. Usually taken from the function definition, but if there's none, JavaScript tries to guess it from the context (e.g. an assignment).
 - `length` -- the number of arguments in the function definition. Rest parameters are not counted.
 
 If the function is declared as a Function Expression (not in the main code flow), and it carries the name, then it is called a Named Function Expression. The name can be used inside to reference itself, for recursive calls or such.