Agreed, for example you can give it a sample FastHTML app, and it will basically review that app pretty much learn/pick up FastHTML (a new Python web framework ~8-9 months old) on the fly without even giving it https://docs.fastht.ml/llms-ctx.txt

Obviously it will do even better if you give it the full documentation but it doesn't do that badly in general with the language when you provide a sample app where it can basically just pick up the patterns of the language/framework.