Add support for configuring a favicon and embed PWA manifest in server-generated-meta

config/description.exs

@@ -987,6 +987,12 @@ config :pleroma, :config_description, [
           "The instance thumbnail can be any image that represents your instance and is used by some apps or services when they display information about your instance.",
         suggestions: ["/instance/thumbnail.jpeg"]
       },
+      %{
+        key: :favicon,
+        type: {:string, :image},
+        description: "Favicon of the instance",
+        suggestions: ["/favicon.png"]
+      },
       %{
         key: :show_reactions,
         type: :boolean,