updated doc for software

doc/source/source_rst/software/architecture.rst

@@ -5,7 +5,7 @@ The OhmPi V2024 software has been completely re-structured to enable increased f
 functionalities used to interact with the OhmPi instrument via a web interface, IoT
 communication protocols (e.g. MQTT) and/or directly through the Python API.
 
-.. figure:: ../../img/architecture.png
+.. figure:: ../../img/software/ohmpi_2024_architecture.png
 
      Software architecture of OhmPi V2024.
 

doc/source/source_rst/software/installation.rst

-Installation
+Getting started
 ************
 
-Step 1: Connect to the Raspberry Pi
-===================================
+Step 1: Set up the Raspberry Pi
+==================================
+First, install an operating system on the Raspberry Pi by following the official instructions_.
+.. _instructions` : https://www.raspberrypi.com/documentation/computers/getting-started.html#install-an-operating-system
+
+Then connect to the Raspberry Pi either via ssh or using an external monitor.
+
+For all questions related to Raspberry Pi operations, please refer to the official documentation_.
+.. _documentation: https://www.raspberrypi.com/documentation/
 
 Step 2: Clone the OhmPi project
 ===============================
 
+You need to clone the OhmPi repository on the Raspberry Pi with the following command:
+.. code-block:: bash
+
+   $ git clone https://gitlab.irstea.fr/reversaal/OhmPi.git
+
 Step 3: Run the installation script
 ===================================
 
@@ -46,4 +58,6 @@ If you need to leave the virtual environment, simply type:
 
 .. code-block:: bash
    
-   $ deactivate
\ No newline at end of file
+   $ deactivate
+
+Following these steps, you are now ready to operate the OhmPi.
\ No newline at end of file