Remove Email Announcements page (outdated)

Author: sarina

source/community/how-tos/receive_announcements_by_email.rst

@@ -9,6 +9,5 @@ Community Home
    how-tos/read_the_roadmap
    references/tutorials
    security_policy/index
-   how-tos/receive_announcements_by_email
    Community Discussion Boards <https://discuss.openedx.org>
    Slack Workspace <https://openedx.org/slack>