Add some missing fields to instanceV2

Signed-off-by: marcin mikołajczak <git@mkljczk.pl>

config/description.exs

@@ -566,6 +566,14 @@ config :pleroma, :config_description, [
           "Cool instance"
         ]
       },
+      %{
+        key: :status_page,
+        type: :string,
+        description: "A page where people can see the status of the server during an outage",
+        suggestions: [
+          "https://status.pleroma.example.org"
+        ]
+      },
       %{
         key: :limit,
         type: :integer,