doc: update README.md

Author: Christophe - CC4

README.md

@@ -12,6 +12,16 @@ The image generated is a minimal Raspberry Pi OS image (headless) with the follo
 
 The image is built by CI on tag push and the artifacts are uploaded to the releases page.
 
+# Using the image
+1. Install the Raspberry Pi Imager from [Raspberry official website](https://www.raspberrypi.com/software/)
+3. Download the latest release from this repository
+4. Open Raspberry Pi Imager and select :
+   - No Filtering
+   - Select the image you downloaded
+   - Select your SD card
+5. Click Next and don't apply custom configuration if asked, everything you need is already in the image
+6. Install and enjoy :)
+
 # pi-gen
 
 Tool used to create Raspberry Pi OS images, and custom images based on Raspberry Pi OS,
@@ -458,4 +468,4 @@ To resolve this, ensure that the following files are available (install them if
 
 You may also need to load the module by hand - run `modprobe binfmt_misc`.
 
-If you are using WSL to build you may have to enable the service `sudo update-binfmts --enable`
+If you are using WSL to build you may have to enable the service `sudo update-binfmts --enable`