release tokens: update wiki to describe release tokens usage (#162)

Instructor-Guide--Assignments--Releasing-Grades.md

@@ -4,6 +4,7 @@
 
 - [Info](#info)
 - [Releasing Grades from Submissions Table](#releasing-grades-from-submissions-table)
+- [Managing Release Tokens](#managing-release-tokens)
 - [Releasing Grades from Grading View](#releasing-grades-from-grading-view)
 - [Unreleasing Grades](#unreleasing-grades)
 
@@ -34,6 +35,19 @@ Once you've selected at least one group, the "Release Marks" button should light
 
 Click on the button and the marking state of selected groups should change from "Complete" to "Released". The students in that group my now view their marks, annotations, feedback files, summary, etc. for the assignment.
 
+## Managing Release Tokens
+
+If "Only allow students to view released marks via a unique URL" has been enabled for this assignment (see [here](./Instructor-Guide--Assignments--Setting-Up.md#properties)), then you can manage release tokens for groups by selecting some groups that have been collected in the submissions have and clicking the "Show Release Tokens" button.
+
+This will open a modal that shows the following data for each selected group:
+
+- The group name (and members)
+- The release token for this group
+- The expiry date of the release token for this group
+- A url that includes the release token as a parameter (this url can be given to the students to directly access the released result)
+
+A student will not be able to view a released result unless they have their release token. MarkUs itself does not make release tokens visible to students as they are to be used as an additional authentication requirement.
+
 ## Releasing Grades from Grading View
 
 MarkUs also gives you the option of releasing grades for a specific group right from the grading view page. Again, once you have finished marking and set the group's marking status to complete, you may release their grades. The "Release Marks" button on the grading view is located to the right of the "Set to Complete" button and will only become clickable once "Set to Complete" has been clicked:

Instructor-Guide--Assignments--Setting-Up.md

@@ -44,6 +44,10 @@ If you wish to allow students to submit URLs check the "Allow students to submit
 
 If you want to give students the ability to submit through the MarkUs API, you can check the "Allow students to submit through the MarkUs API" box. This is necessary if you plan on creating or using an external plugin that allows students to submit assignments such as the MarkUs Jupyter Extension.
 
+If you want to prevent students from automatically being able to view released marks select the "Only allow students to view released marks via a unique URL" box. Once you release the marks for this assignment, you can generate a unique token for each student. The student will need to enter this token in order to view the results.
+> :spiral_notepad: **NOTE:**
+> These tokens can be expired so this is a good way to make results available to students only by request and only for a specific period of time.
+
 Please see the [Peer Review](Instructor-Guide--Assignments--Peer-Review.md) page for more information on Peer Review.
 
 ### Required Files

Student-Guide.md

@@ -108,6 +108,12 @@ Once your submssion for an assignment has been marked, the Result tab will becom
 - See your mark for this assignment broken down by criteria from the "Marks" tab.
 - See a summary of your marks (including any bonuses or deductions) as well as any notes or overall comments on the "Summary" tab.
 
+### Release Tokens
+
+If your instructor chooses, you may need a "release token" to view your results. A release token is a series of random numbers and letters that is unique to your result.
+
+If a release token is required, you can request one from your instructor once they have finished grading your assignment. When you go to the Result tab you will be asked to enter your release token to view the Result page.
+
 ## Submit a Remark Request
 
 If your instructor has enabled remark requests for your assignment *and* the deadline to submit remark requests has not yet passed, you can submit a remark request from the "Remark Request" tab on the [Results](#view-results) page.