added clear assessments section (#444)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **Documentation**
* Improved formatting in the assessment authoring guide: corrected image
alignment and alt-text presentation for clearer reading.
* Added a "How to Clear Assessment Answers" section with step-by-step
instructions and before/after visuals to help instructors manage
responses.
* Updated the Collapsible Content example delimiter in the Markdown
authoring guide for more consistent rendering.

<sub>✏️ Tip: You can customize this high-level summary in your review
settings.</sub>
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

Author: LolaValente

source/img/guides/clear_assessment_answers.png

@@ -48,8 +48,8 @@ To add a new assessment for an assignment, follow these steps:
 1. Open the assignment in the course, and click the **Edit** button to open the Guide Editor. You can also click the **Tools** menu and choose **Guides > Edit**.
 2. Click the **Assessments** button and choose the type of assessment you want to add to the assignment.
 
-   .. image:: /img/guides/add_assessment.png
-      :alt: Add Assessment
+.. image:: /img/guides/add_assessment.png
+   :alt: Add Assessment
 
 3. Fill the appropriate fields and click **Create**.
 
@@ -71,4 +71,20 @@ Refer to the specific topics for the type of assessment:
 - :ref:`Parsons Puzzle <parsons-puzzle>`
 - :ref:`Random Assessment <random>`
 - :ref:`LLM Rubric Grader <llm-based-rubric>`
-- :ref:`LLM Rubric Autograde <llm-based-auto-rubric>`
+- :ref:`LLM Rubric Autograde <llm-based-auto-rubric>`
+
+
+How to Clear Assessment Answers
+-------------------------------
+
+To clear assessment answers, navigate to the Education menu and click **Clear Assessment Answers**. A confirmation dialog will appear—click **Yes** to proceed. This removes all answered questions from the database, resetting the assessment to its initial state as if it had never been run.
+
+Before:
+~~~~~~~
+.. image:: /img/guides/clear_assessment_answers.png
+   :alt: Clear Assessment Answers
+
+After:
+~~~~~~
+.. image:: /img/guides/clear_assessment_answersafter.png
+   :alt: Clear Assessment Answers

source/img/guides/clear_assessment_answersafter.png

@@ -346,7 +346,7 @@ Collapsible content is useful for providing information that students can reveal
   - If you want the content to show by default, use `<details  open>`.
 
 Example
-"""""""
+~~~~~~~
 
 .. image:: /img/guides/collapsible.png
     :alt: Collapsible content