zabernical-phenakist-ratoon / 9mm-shield-magazine-extension

So, you've got a shinny new M&P 9mm shield ... but it ships with a short magazine and your hand is too big for a good grip on it. Extended magazines are on back order or can only be had via a select few resellers who are charging ~$20-$30 more than MSRP. Here is a temporary fix you might like to try. See the readme for further details.