Hi Amine,
We are working to update the docs, but for the time being here are some notes that might assist you:
1) We are still using CourseTalk, we have just extended it to be more flexible to using a new reviews tool if an openedx instance does not want to use coursetalk.
2) In the file lms/envs/common.py you will see a COURSE_REVIEWS_TOOL_PROVIDER_FRAGMENT_NAME. This defines a template that is loaded into the reviews page when the page loads. The other settings (COURSE_TALK_READ_ONLY_SOURCE, COURSE_TALK_WRITE_ONLY_SOURCE) define the javascript imports needed to get the reviews widget working.
3) The course reviews tool in the course home sidebar shows up based off the is_enabled function in course_experience/[lugins.py CourseReviewsTool class.
Perhaps that can help - if it all works you should be able to see http://{your_local_env}/courses/course-v1:edX+DemoX+Demo_Course/course/reviews