Add book recommendation for mentor : Olga Volkova

[mads6879]

Task

Add recommendations for Olga Volkova in Resources section.
(Use the same format that has been used for other mentors e.g. Eleonora)

Books
Designing Machine Learning Systems
Machine Learning System Design Interview

Resources tab

Acceptance criteria

Screenshot of the resources tab

[OVolkova]

Could I please also add one more book to the list:
Designing Data-Intensive Applications