add image accessibility best practice documentation URL and pass through to...

add image accessibility best practice documentation URL and pass through to studio-frontend edit image modal

cms/envs/help_tokens.ini

@@ -33,6 +33,7 @@ container = course_author:developing_course/course_components.html#components-th
 video = course_author:video/index.html
 certificates = course_author:set_up_course/studio_add_course_information/studio_creating_certificates.html
 content_highlights = course_author:developing_course/course_sections.html#set-section-highlights-for-weekly-course-highlight-messages
+image_accessibility = course_author:accessibility/best_practices_course_content_dev.html#use-best-practices-for-describing-images
 
 # below are the language directory names for the different locales
 [locales]

cms/templates/container.html

@@ -174,7 +174,10 @@ from openedx.core.djangolib.markup import HTML, Text
           <div id="edit-image-modal">
             <%static:studiofrontend entry="editImageModal">
               {
-                "lang": "${language_code | n, js_escaped_string}"
+                "lang": "${language_code | n, js_escaped_string}",
+                "help_tokens": {
+                    "image_accessibility": "${get_online_help_info('image_accessibility')['doc_url'] | n, js_escaped_string}"
+                }
               }
             </%static:studiofrontend>
           </div>