add notes

Author: rarruda

Steepfile

@@ -3,11 +3,14 @@ D = Steep::Diagnostic
 target :lib do
   signature "*.rbs"
 
+  # Note: All client-exposed methods/types should now have type signatures / rbs support
   check "lib/unleash/client.rb"
   check "lib/unleash/context.rb"
   check "lib/unleash/variant.rb"
   check "lib/unleash/scheduled_executor.rb"
 
+  # TODO: add signatures to the rest
+  # Mostly internal SDK files.
   ignore "lib/unleash/bootstrap"
   ignore "lib/unleash/strategy/*.rb"
   ignore "lib/unleash/util"