Document recent platform features

[mintlify]

Added documentation for new dashboard features, discussion board enhancements, and assignment improvements based on recent staging commits. Created four new dashboard pages and updated existing documentation to cover karma system, error pins, leaderboards, drag-and-drop image uploads, enhanced autograder reruns, date picker improvements, score capping, and annotation usability enhancements.

New files:

• staff/assignments/grading-status-dashboard.mdx
• staff/assignments/assignment-dashboard.mdx
• staff/assignments/test-insights-dashboard.mdx
• staff/assignments/security-dashboard.mdx

Updated files:

• students/discussion-board.mdx
• staff/discussion.mdx
• students/assignments/create-submission.mdx
• staff/assignments/intro.mdx
• staff/assignments/autograding.mdx
• staff/assignments/handgrading.mdx
• docs.json

[coderabbitai]

Important

Review skipped

Bot user detected.

To trigger a single review, invoke the @coderabbitai review command.

You can disable this status message by setting the reviews.review_status to false in the CodeRabbit configuration file.

---

_{Comment @coderabbitai help to get the list of available commands and usage tips.}