added issues and some additional descriptions

docs/components/single-page-notification-button.md

@@ -46,7 +46,10 @@ howItWorks:
 
 
   Once a user selects the button, they are redirected to a page where they can create a GOV.UK One Login.
-  [Example](https://www.gov.uk/email/subscriptions/single-page/new?topic_id=download-the-hmrc-app)
+  <a class="govuk-link" href="https://www.gov.uk/email/subscriptions/single-page/new?topic_id=download-the-hmrc-app" rel="noopener noreferrer" target="_blank">Example (opens in a new tab)</a>
+
+
+  If the user has already subscribed to email notifications about the current page, display the “Stop getting emails about this page” state.
 
 
   View this component and all its variations in the <a class="govuk-link" href="https://components.publishing.service.gov.uk/component-guide/single_page_notification_button" rel="noopener noreferrer" target="_blank">Component Guide (opens in a new tab)</a>.'
@@ -94,6 +97,18 @@ designSystems:
 issues:
   # To add additional issues duplicate the the fields below (adhering to the formating) but increase the count by one integer.
   0:
+    # Both title and link are REQUIRED in order to display this information on the page.
+    title: Does the fact that you need a gov.uk account keep people from signing up for updates? 
+    link: https://github.com/alphagov/govuk-design-guide/issues/164
+  1:
+    # Both title and link are REQUIRED in order to display this information on the page.
+    title: The difference between this component and the Subscription Link is unclear.
+    link: https://github.com/alphagov/govuk-design-guide/issues/165
+  2:
+    # Both title and link are REQUIRED in order to display this information on the page.
+    title: The component lives in context of other components but the lockup is inconsistent.
+    link: https://github.com/alphagov/govuk-design-guide/issues/166
+  3:
     # Both title and link are REQUIRED in order to display this information on the page.
     title: #Delete this comment before entering the title of the GitHub issue.
     link: #Delete this comment before entering the URL of the corresponding GitHub issue.