docs: mention hardware and RFCs in README (#215)

This PR mentions hardware and RFC folders in the main README

README.md

@@ -25,15 +25,19 @@ The project layout contains the following folders:
 
 * [`assets/`] - images and files used for READMEs and other documentation
 * [`book/`] - This is the source of "the mnemOS book"
+* [`hardware/`] - Hardware designs for MnemOS systems, including CAD files and documentation
 * [`source/`] - This folder contains the source code of the cross-platform kernel, userspace, and related libraries
 * [`platforms/`] - This folder contains code specific to each targeted hardware and simulation platform
+* [`rfcs/`] - MnemOS design RFCs
 * [`tools/`] - This folder contains desktop tools used for working with MnemOS
 
 [`assets/`]: ./assets/
 [`book/`]: ./book/
+[`hardware/`]: ./hardware/
 [`source/`]: ./source/
 [`platforms/`]: .platforms/
 [`tools/`]: ./tools/
+[`rfcs/`]: ./rfcs/
 
 ## Getting Started