docs: modify the readme file

Author: maksyuki

.github/workflows/unit-test.yml

@@ -14,4 +14,6 @@ jobs:
         run: |
           cd rtl
           chmod +x scripts/install.sh
-          make install
+          make install
+          chmod +x scripts/setup.sh
+          make setup

README.md

@@ -3,6 +3,9 @@
     <h2 align="center">TreeCore CPU: A series of riscv processors written from scratch</h2>
 </p>
 <p align="center">
+   <a href="https://github.com/microdynamics-cpu/tree-core-cpu/actions">
+    <img src="https://img.shields.io/github/workflow/status/microdynamics-cpu/tree-core-cpu/unit-test/main?label=unit-test&logo=github&style=flat-square">
+    </a>
     <a href="./LICENSE">
       <img src="https://img.shields.io/github/license/microdynamics-cpu/tree_core_cpu?color=brightgreen&logo=github&style=flat-square">
     </a>