updated layout and note box (#402)

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

## Summary by CodeRabbit

* **Documentation**
* Improved the visual layout of the instructions for adding teachers,
using a two-column table with images embedded alongside text.
* Enhanced the appearance of notes with styled backgrounds and borders
for better emphasis.
* Updated internal documentation references to external links that open
in new tabs.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

Co-authored-by: Lola Valente <lvalente@codio.com>

Author: LolaValente

source/instructors/admin/organization/add-teachers.rst

@@ -27,10 +27,17 @@ After setting up your organization, you can add teachers to give them access to
      :alt: Members
 
 
-4. Click the **Add Member** button, enter in the **Teacher Email** and in the **invite as** section select **Teacher** from the drop down.
++-----------------------------------------------------------------------+--------------------------------------------------------------------------------------------------+                                                                                                                                                   
+| 4. Click the **Add Member** button, enter in the **Teacher Email**    |                                                                                                  |
+|    and in the **invite as** section select **Teacher** from the       |                                                                                                  |
+|    drop down.                                                         |                                                                                                  |
+|                                                                       | .. image::                                                                                       |
+|                                                                       |    /img/manage_organization/                                                                     |
+|                                                                       |    inviteteacher.png                                                                             |
+|                                                                       |    :alt: Invite Teacher                                                                          |
++-----------------------------------------------------------------------+--------------------------------------------------------------------------------------------------+
+
 
-  .. image:: /img/manage_organization/inviteteacher.png
-     :alt: Invite Teacher
 
 
 +-------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
@@ -50,13 +57,18 @@ After setting up your organization, you can add teachers to give them access to
   An email is sent to the teacher that contains a link to sign up. Upon completing the sign up process, they are added to your organization.
 
 
-.. Note:: They must use the same email address to which the invitation was sent; otherwise, they will not be added to the organization. 
-    
-    This invitation is valid for 7 days. If it is not used within that time frame, it will expire, and the recipient will no longer be able to use it to join the organization. In such cases, you will need to resend the invitation. All pending invitations are displayed and you have the option to **Resend** or **Revoke** the invitation.
+
+.. raw:: html
 
 
+ <div style= " margin: 0 0 10px 20px; padding: 10px; background: #f0f0f0; border: 3px solid #00ece5;">
+ <strong>Note:</strong> They must use the same email address to which the invitation was sent; otherwise, they will not be added to the organization. This invitation is valid for 7 days. If it is not used within that time frame, it will expire, and the recipient will no longer be able to use it to join the organization. In such cases, you will need to resend the invitation. All pending invitations are displayed and you have the option to <strong>Resend</strong> or <strong>Revoke</strong> the invitation.
 
+ </div>
 
-.. Note:: If you already have courses set up, you can add and invite teachers directly into your course(s). See :ref:`Add or Remove Teachers in a Course <add-teachers>`. You can then add them as an :ref:`organization owner <org-owners>` so they can then manage and create courses, and have full Admin access to the organization.
+.. raw:: html
 
 
+ <div style= " margin: 0 0 10px 20px; padding: 10px; background: #f0f0f0; border: 3px solid #00ece5;">
+ <strong>Note:</strong> If you already have courses set up, you can add and invite teachers directly into your course(s). See <a href="https://docs.codio.com/instructors/setupcourses/add-teachers.html#add-teachers" target="_blank">Add or Remove Teachers in a Course</a>. You can then add them as an <a href="https://docs.codio.com/instructors/admin/organization/add-remove-org-owners.html#org-owners" target="_blank">organization owner</a> so they can then manage and create courses, and have full Admin access to the organization.
+ </div>