Shorter, more apt names for folders within shared/
Three new commands: \baseQR, \setbaseQR and \embedQR defined ...

\setbaseQR is inserted from within make after the SHA1SUM of the .tex
file has been found

Thereafter, \embedQR is called in lieu of \insertQR.
There is no need to provide a QR code because that is got from whatever
is stored in \baseQR (by \setbaseQR)