Add two additional badges to show contributors and last commit

Also add additional start option "Stable branch". As sources are now (mainly) frozen, this is worth to mention and recommend.

README.md

@@ -4,7 +4,9 @@
   </a><br>
   <strong>Armbian Linux Build Framework</strong><br>
 <br>
-<a href=https://github.com/armbian/os><img alt="Artifacts generation" src="https://img.shields.io/github/actions/workflow/status/armbian/os/complete-artifact-matrix-all.yml?logo=githubactions&label=Build&style=for-the-badge&branch=main&logoColor=white"></a>
+<a href=https://github.com/armbian/build/graphs/contributors><img alt="GitHub contributors" src="https://img.shields.io/github/contributors-anon/armbian/build?logo=stackexchange&label=Contributors&style=for-the-badge&branch=main&logoColor=white"></a>
+<a href=https://github.com/armbian/os><img alt="Artifacts generation" src="https://img.shields.io/github/actions/workflow/status/armbian/os/complete-artifact-matrix-all.yml?logo=dependabot&label=CI%20Build&style=for-the-badge&branch=main&logoColor=white"></a>
+<a href=https://github.com/armbian/build/commits/main><img alt="GitHub last commit (branch)" src="https://img.shields.io/github/last-commit/armbian/build/main?logo=github&label=Last%20commit&style=for-the-badge&branch=main&logoColor=white"></a>
 </p>
 
 ## Table of contents
@@ -38,6 +40,8 @@
 
 ### Start with the build script
 
+#### Development branch:
+
 ```bash
 apt-get -y install git
 git clone --depth=1 --branch=main https://github.com/armbian/build
@@ -45,6 +49,16 @@ cd build
 ./compile.sh
 ```
 
+#### Stable branch:
+
+```bash
+apt-get -y install git
+git clone --depth=1 --branch=v23.11 https://github.com/armbian/build
+cd build
+./compile.sh
+```
+
+
 <a href="#how-to-build-an-image-or-a-kernel"><img src=".github/README.gif" alt="Armbian logo" width="100%"></a>
 
 - Interactive graphical interface.