help: Add example email invitation image to "Invite new users".

Adds a link to the section on email invitations to the invite user
modal next to the label for the emails input.

Fixes #29376.

help/invite-new-users.md

@@ -65,6 +65,10 @@ users** menu option if you have permission to invite users.
     Any restrictions on [allowed authentication
     methods](/help/configure-authentication-methods) are not applied.
 
+## Example email invitation
+
+![Email invitation](/static/images/help/example-invitation-email.png)
+
 ## Create a reusable invitation link
 
 {start_tabs}

web/templates/invite_user_modal.hbs

@@ -9,7 +9,9 @@
     <div class="input-group">
         <div id="invite_users_option_tabs_container"></div>
         <div id="invitee_emails_container">
-            <label for="invitee_emails" class="modal-field-label">{{t "Emails (one on each line or comma-separated)" }}</label>
+            <label for="invitee_emails" class="modal-field-label">{{t "Emails (one on each line or comma-separated)" }}
+                {{> help_link_widget link="/help/invite-new-users#send-email-invitations" }}
+            </label>
             <div class="pill-container {{#unless user_has_email_set}}not-editable-by-user{{/unless}}">
                 <div class="input" {{#if user_has_email_set}}contenteditable="true"{{/if}}></div>
             </div>