update README after microwatt 'adventures'

README.md

@@ -1,5 +1,12 @@
 # Updated Sonar System
 
+## Repo Layout
+
+```
+hardware/ - Directory for any hardware designs
+  pmod/ - A PMOD interface board, using 4 ADCs with LVDS converters to get data across PMOD
+```
+
 ## Design Goals
 
 - 4x 20MSPS channels @ > 8 bits
@@ -46,7 +53,7 @@
 The plan is to use LiteX and let it do most of the heavy lifting. Components to
 generate:
 
-- Softcore (microwatt probably, I'm feeling a bit hipster)
+- Softcore (some RISC-V core)
 - Main memory bus
 - DMA engine
 - Gigabit Ethernet MAC
@@ -57,12 +64,9 @@ demonstrate access to the bus, and then I can keep adding functionality.
 
 ## Software Planning
 
-I should be able to target the microwatt with Rust, hopefully do some embassy work and
-then that gives me a good dev environment.
+Will try to use embassy on RISC-V if I can.
 
 Should make sure to have a debug port available as early as possible.
 
 I will make the interface as generic as possible, so it should be easy to swap out, but I
 will start by targetting zmq so I can change as little of the software stack as possible.
-
-[Reference for custom target triple](https://docs.rust-embedded.org/embedonomicon/custom-target.html)