Good question! DNA is double-stranded, and the template strand is converted as you described, but the coding strand corresponds to the RNA in the way the kata description explained. When DNA is sequenced, it's often that the coding strand data is shown, so the mental effort to convert those to codons and amino acids is a little bit less.

A should convert to T and T should convert to U if its converting from DNA to RNA. Also, C converts to G while G converts to C.