add blk video

README.md

@@ -40,6 +40,8 @@ M3 Tap | Extensively |
 
 [RCTBLK-90-025ALU Fusion CAD File](cad/RCTBLK-90-025ALU_v6.f3d)
 
+![](video/SEQ-rct-add-blk-enc.mp4)
+
 # REF
 
 Find [Open Assemblies Hardware Reference](https://github.com/jakeread/openassemblies/blob/master/hardware.md) for shorthands etc.