[Documentation:TAGrading] sorting and navigation (Submitty#147)

* Documentation changes.

* Added images

* Changes

Author: Kevin-MM

_data/links.yml

@@ -32,6 +32,7 @@
   children:
     - name: Overview
       link: ../grader
+    - name: Sorting and Navigation
     - name: Resolving a Grade Inquiry
       link: grade_inquiry_grader
 

_docs/grader/sorting_and_navigation.md

@@ -0,0 +1,46 @@
+---
+category: Grader
+title: Sorting and Navigation
+---
+
+### Sorting Options
+
+![](/images/sorting_and_navigation/index.png)
+
+On the grading index page there are several options available to sort students.  Many options allow for sorting
+in ascending or descending order.  Select the option once for ascending order, press it a second time for descending.
+
+**User ID:** Sort students alphabetically by their user ID.
+
+**First Name:** Sort students alphabetically by their first name.
+
+**Last Name:** Sort students alphabetically by their last name.
+
+**Random:** Sort students in a pseudo-randomized order.  The random order is different for each gradeable.  The purpose
+of this sorting order is to help distribute bias that comes along with always being graded first or last for each assignment.
+
+### Prev / Next Student Buttons
+
+![](/images/sorting_and_navigation/prev_next_buttons.png)
+
+These buttons allow the grader to move to the next submission.
+
+**Limited access graders:** These buttons will only move to submissions within the grader's assigned sections.
+
+**Full access graders:** These buttons can be used to browse submissions from all sections.
+
+### Prev / Next Assigned Ungraded Student Buttons
+
+These buttons allow the grader to move to the previous or next ungraded submission.
+It is worth noting that these buttons will only move to ungraded submissions within a grader's assigned sections.
+
+With no component open, selecting the next ungraded student button will move to the next submission with *any* component
+ungraded.  This mode is useful when a grader is responsible for grading all components for a given submission. *(See image below)*
+
+![](/images/sorting_and_navigation/closed_components.png)
+
+When a component is open, selecting the next ungraded student button will move to the next submission with
+*that specific component* ungraded.  This mode is most useful when multiple graders are grading a single submission, each
+working on different components. *(See image below)*
+
+![](/images/sorting_and_navigation/open_components.png)