Interactive QR code URLs resolve to wrong place

[siwelwerd]

For example, Figure 1 in the print version is accompanied by a QR code pointing to the (dead) URL htps://tbil.org/LE1-interactive-add-vectors.html .

[siwelwerd]

One fix would be to change the baseurl in the publication file, but then we would have to have different publication files for different books. Maybe I will just assign this to @StevenClontz to think about.