fix: add documentation to candidate app

[norppaa]

WHY:

Adds documentation to AnsweredQuestion.svelte, QuestionsStartPage.svelte and UnAnsweredQuestions.svelte

What has been changed (if possible, add screenshots, gifs, etc. )

Adds documentation to AnsweredQuestion.svelte, QuestionsStartPage.svelte and UnAnsweredQuestions.svelte

Check off each of the following tasks as they are completed

• [x] I have reviewed the changes myself in this PR. Please check the self-review document
• [ ] I have added or edited unit tests.
• [ ] I have run the unit tests successfully.
• [ ] I have run the e2e tests successfully.
• [ ] I have tested this change on my own device.
• [ ] I have tested this change on other devices (Using Browserstack is recommended).
• [ ] I have tested my changes using the WAVE extension
• [x] I have added documentation where necessary.
• [ ] Is there an existing issue linked to this PR?

Clean up your git commit history before submitting the pull request!