Neurolibre Book button and Github Code buttons have same URLs

[Shotgunosine]

Looks great overall, I just noticed a small issue when I was trying to find the code for the books. The Neurolibre Book button and the Github Code buttons both point to the Neurolibre Book URL. I was able to find the code linked from the book page itself, but it's a little unexpected that the code button doesn't go to the github repo.

[pbellec]

indeed, thanks for pointing it out!

[agahkarakuzu]

Thank you @Shotgunosine! 0205927 should fix it now.

@pbellec some of the books are resourced from outside, for them I added temporary ext in the yamls.