update readme

README.md

@@ -1,9 +1,20 @@
 ## RGB2SVIDEO
 
-This device converts RGB + Sync analog signal to S-Video (and also Composite).
+This device converts 15KHz RGB + Sync analog video signal to S-Video or CVBS (composite) signal.
-Both PAL and NTSC supported (you should choose one at build).
+Both PAL and NTSC are supported (you should choose one at build).
 
-PCB size: 37.2x16.4mm
+[![photo](images/thumb.photo.jpg)](images/photo.jpg?raw=true)
 
-[![photo](out/pcb3d-top.rev.A2.webp)](out/pcb3d-top.rev.A2.webp?raw=true)
+### Revision C PCB
-[![photo](out/pcb3d-bottom.rev.A2.webp)](out/pcb3d-bottom.rev.A2.webp?raw=true) 
+This PCB is based on AD724 chip and designed to fit into DSUB shell.
+
+[release/pcb.rev.C.pdf](release/pcb.rev.C.pdf?raw=true) - schematic and bill of materials  
+[release/bom_interactive.rev.C.html](https://htmlpreview.github.io/?https://github.com/UzixLS/rgb2svideo/blob/master/release/bom_interactive.rev.C.html) - interactive BOM  
+[release/gerber.rev.C.zip](release/gerber.rev.C.zip) - fabrication files  
+
+### Revision A PCB
+This PCB is based on BH7236AF/KA2198BD/CXA1645/CXA2075 chips and designed to fit into AK-S-71 shell.
+
+[release/pcb.rev.A2.pdf](release/pcb.rev.A2.pdf?raw=true) - schematic and bill of materials  
+[release/bom_interactive.rev.A2.html](https://htmlpreview.github.io/?https://github.com/UzixLS/rgb2svideo/blob/master/release/bom_interactive.rev.A2.html) - interactive BOM  
+[release/gerber.rev.A2.zip](release/gerber.rev.A2.zip) - fabrication files