[Documentation:InstructorUI] Update current grade override view (#688)

Rename `studentOveriden.png` to `studentOveridden.png`. Changed most of
the images to look like the current UI. Removed
`images/OverrideSelected.png` as it is not being used.

Current:


https://github.com/user-attachments/assets/569b17f4-5285-45c9-8685-cabe4e53d427

New:


https://github.com/user-attachments/assets/081ba79f-0fbc-4510-851a-7e5eb3db5c27

Author: williamschen23

_docs/instructor/course_management/grade_override.md

@@ -68,7 +68,7 @@ any) and detailed rubric manual grading feedback (if any).  The
 overridden score will be visible only from
 [Rainbow Grades](/instructor/course_settings/rainbow_grades/index).
 
-![](/images/studentOverriden.png)
+![](/images/studentOverridden.png)
 
 
 ### Grader View
@@ -77,7 +77,7 @@ When a grader interacts with the grading details page for a gradeable
 that has overridden grades for one or more students, the button from
 the index page will be labeled "Overridden".
 
-![](/images/TAOverriden1.png)
+![](/images/TAOverridden1.png)
 
 If the grader selects the grading page for a student that has been
 overridden the page is highlighted in yellow as an alert.  The grader
@@ -87,4 +87,4 @@ be available to the student (see above).  But these scores will not be
 used in calculating the students overall course grade in
 [Rainbow Grades](/instructor/course_settings/rainbow_grades/index).
 
-![](/images/TAOverriden2.png)
+![](/images/TAOverridden2.png)