Development: Document the exam timeline

docs/user/exams/instructors_guide.rst

@@ -451,10 +451,23 @@ If you want you can also enable the :ref:`second correction <Before the exam's a
 
 - At the bottom of the page you will find the option |check_plagiarism|.
 
+3.4 Exam Timeline
+^^^^^^^^^^^^^^^^^
+- Artemis stores the current state of a submission for text, modeling, and quiz exercises every 30s or whenever the student clicks the save button.
+- As instructor, you have the possibility to view all those states as well as the submissions for file-upload or programming exercises using the exam timeline.
+- The exam timeline is available on the details page of a student exam when the student exam has been submitted by clicking on the button |exam_timeline|. If the exam has not been submitted yet, the exam timeline button is disabled and shows an explanatory tooltip.
+- The exam timeline shows all submissions of the student in chronological order. You can navigate between the different timestamps on the slider or navigate between different exercises using the navigation bar below the timeline
+- For programming exercises, you can view a git diff between the currently selected submission and the previous submission or the template of this exercise.
+
+.. figure:: instructor/exam_timeline_example.png
+     :alt: Exam timeline
+     :align: center
+
+
 
 .. _exam_grading_key:
 
-3.4 Grading Key
+3.5 Grading Key
 ^^^^^^^^^^^^^^^
 - Optionally, you can create a grading key for your exam by clicking |grade_key| at the top of the exam's detail page.
 - Defining a grading key allows the exam score to be converted to a grade automatically by Artemis, students are then able to see their own grades after the specified `Release Date of Results`.
@@ -567,6 +580,7 @@ Artemis collects the complaints submitted by the students during the :ref:`stude
 .. |assess_test_runs| image:: instructor/buttons/assess_test_runs.png
 .. |assess_unsubmitted_student_exams| image:: instructor/buttons/assess_unsubmitted_student_exams.png
 .. |check_plagiarism| image:: instructor/buttons/check_plagiarism.png
+.. |exam_timeline| image:: instructor/buttons/exam_timeline.png
 .. |configure_grading| image:: instructor/buttons/configure_grading.png
 .. |course_management| image:: instructor/buttons/course_management.png
 .. |create_new_exam| image:: instructor/buttons/create_new_exam.png