[Doc] Update README about fabric key and apply minor format

ARCH/README.md

@@ -2,10 +2,15 @@
 This directory contains the FPGA architecture description files for OpenFPGA tool suites.
 All the FPGA architecture description are binded to the opensource skywater 130nm PDK
 
+---
+
 * Keep this folder clean and organized as follows
   - **vpr\_arch**: FPGA architecture description for VPR
   - **openfpga_arch_template**: template FPGA architecture description for OpenFPGA.
   - **openfpga_arch**: adapted FPGA architecture description for OpenFPGA which are converted from the templates.
+  - **fabric\_key**: the fabric key files used to custom floorplanning in FPGA netlists. See details [**here**](https://openfpga.readthedocs.io/en/master/manual/arch_lang/fabric_key/)
+
+---
 
 * Note: 
   - Please **ONLY** place folders under this directory

README.md

@@ -8,8 +8,9 @@ FPGA tape-outs using the open-source Skywater 130nm PDK and OpenFPGA
 git clone https://github.com/LNIS-Projects/skywater-openfpga.git
 python3 SCRIPT/repo_setup.py --openfpga_root_path ${OPENFPGA_PROJECT_DIRECTORY}
 ```
+---
 
-* If you have openfpga repository cloned in the level of this project, you can simple call
+* If you have openfpga repository cloned at the same level of this project, you can simple call
 ```bash
   python3 SCRIPT/repo_setup.py
 ``` 
@@ -31,6 +32,8 @@ Otherwise, you should provide full path for the --openfpga\root\_path
                     Keep a README inside the folder about the ICC2 version and how-to-use.
   - **MSIM**: workspace of verification using Mentor ModelSim
 
+---
+
 * Note: 
   - Please **ONLY** place folders under this directory.
     README should be the **ONLY** file under this directory