Add guide for archiving mailing lists

Signed-off-by: Michal Konecny <mkonecny@redhat.com>

modules/howtos/pages/archive_list.adoc

@@ -0,0 +1,26 @@
+= How to archive mailing list
+
+[NOTE]
+====
+You need to be mailman admin to be able to follow this guide.
+====
+
+. Go to the link:https://lists.fedoraproject.org/admin/lists/[mailman site]
+on the top right corner select `Sign In`
++
+Do not login through the username and password fields, login using the
+third party `Fedora` link to assume fas permissions
++
+. Find the mailing list you want to archive and click on it
+
+. Set settings -> list identity -> to have [ARCHIVED] at the end of the display name
+
+. Save changes
+
+. Set settings -> message acceptance -> reject with notification (you need to do this twice)
+
+. Save changes
+
+. Set settings -> subscription policy -> confirm then moderate
+
+. Save changes

modules/sysadmin_guide/pages/index.adoc

@@ -190,6 +190,7 @@ xref:developer_guide:sops.adoc[Developing Standard Operating Procedures].
 In this section is list of guides for common tasks that are done in Fedora Infrastructure.
 
 * xref:howtos:access_rabbitmq_ui.adoc[How to access the rabbitmq administrative UI]
+* xref:howtos:archive_list.adoc[How to Archive mailing list]
 * xref:howtos:archive-old-fedora.adoc[How to Archive Old Fedora Releases]
 * xref:howtos:add_a_package_to_infra_tag.adoc[How to add a package to an infra tag]
 * xref:howtos:add_external_hardware_to_vpn.adoc[Add external servers to vpn]