Update the Session library docs

Signed-off-by: Michael <michael@webstart.bg>
Added class reference to the session docs

Signed-off-by: Michael <michael@webstart.bg>
refactored the class reference in session.rst to properly reflect the session class

Signed-off-by: Michael <michael@webstart.bg>
Merge pull request #2666 from xxaxxo/feature/user-guide-cleanup

Update the Session library docs