Merge pull request #232 from zoyakostyreva/hyperskill_links_with_utm

Hyperskill links. UTM tags added

Author: Geravant

Classes and objects/Call a method from another method/task.md

@@ -4,4 +4,4 @@ As we discussed before, methods may call other methods by using method attribute
 Use this knowledge to complete the `exponentiate` method of the `Calculator` class. It should
 call the `multiply` method to calculate the result.
 
-For more structured and detailed information, you can refer to [this Hyperskill knowledge base page](https://hyperskill.org/learn/step/6931).
+For more structured and detailed information, you can refer to [this Hyperskill knowledge base page](https://hyperskill.org/learn/step/6931?utm_source=jba&utm_medium=jba_courses_links).

Classes and objects/Class and Instance Variables 2/task.md

@@ -9,4 +9,4 @@ Implement the method `add_city` that will append a city name to the `all_cities`
 
 In the `__init__` method, call the `add_city` method to add the city name to the list upon object initialization.
 
-For more structured and detailed information, you can refer to [this Hyperskill knowledge base page](https://hyperskill.org/learn/step/6981).
+For more structured and detailed information, you can refer to [this Hyperskill knowledge base page](https://hyperskill.org/learn/step/6981?utm_source=jba&utm_medium=jba_courses_links).