Figure 2 missing M_d symbol in qubits 101

[amopremcak]

Figure 2 uses symbol M, but section surrounding figure uses M_d.

[DanielSank]

Figure 2 has M_d. You may need to rebuild the pdf files from the svg files. Use the make-figures script to do that automatically if you have Python and Inkscape installed.

[amopremcak]

Babby done goofed