update production files in-tree

README.md

@@ -2,6 +2,16 @@
 
 A wireless, low-profile 47/48-key keyboard PCB.
 
+## production files
+
+works with JLCPCB, haven't tried any other production houses, ymmv
+
+- Gerbers: kicad plot output in `48ish_soldered_out` (pre-zipped for upload in `48ish_soldered_out.zip`)
+- Board assembly:
+  - Only parts on the backside need to be assembled
+  - BOM: `48ish_soldered_bom.csv` (not generated by kicad; includes specific JLCPCB part numbers, you may want to shop around for alternatives)
+  - Placements: `48ish_soldered-bottom-pos.csv` (generated by kicad, with column names manually edited to reflect [JLCPCB's requirements](https://jlcpcb.com/help/article/pick-place-file-for-pcb-assembly))
+
 ## firmware???
 
 i wrote a zmk shield for this but dude i am not figuring out the zmk local build steps. go look at [the github repo for the shield firmware](https://github.com/ewwwin/zmk-shield-48ish) and grab the firmware from the latest github actions run, i do not care