Hardware release for Mk4 rev D

hardware/README.md

@@ -9,11 +9,17 @@ researchers who wish to analyse the Coldcard more completely.
 
 # Schematic
 
+![](schematic-mark4d.png)
+
+`schematic-mark4d.png`
+
+This is the Mark4 rev D schematic.
+
 ![](schematic-mark3b.png)
 
 `schematic-mark3b.png`
 
-This is the Mark3 rev B schematic. It's just one page and pretty simple.
+This is the Mark3 rev B schematic.
 
 
 # BOM - Bill of Materials
@@ -30,11 +36,14 @@ Not included are these minor bits:
 - the secure bag (with barcode serial number)
 - pin-recovery card
 
+`bom-mark4d.xlsx`
+
+- Same for Mk4 rev D.
 
 # Important
 
 - No promises that these files are 100% current because we do make quality improvements.
 - Copyright of these files, and all design elements of the Coldcard remain with Coinkite Inc.
-- This information is for research and testing purposes only no warranties. 
+- This information is for research and testing purposes only---no warranties. 
 - **Coinkite does not grant license of this information for comercial use.**