Add user accounts

[JRIngram]

Feature Request - Add user accounts

Describe the feature

Accounts should be added, so that each user can have their own quizzes and cards that cannot be seen or interacted with by other users.

Example user stories

Given I am user 'A'
When I am logged in
Then I can create cards and quizzes
And I can study them

Given I am user B
When I am logged in
Then I cannot see cards and quizzes created by user A

Additional context

This will require a large amount of work:

• Login screens
• Authentication and Authorisation
• Managing quizzes and cards for individual users