Add recommendations for ARM architecture users (#239)

Author: svquick

02_virtualization_and_containers/virtualmachines_containers_exercise.md

@@ -83,6 +83,7 @@ This exercise consists of the following main steps:
     - 2 GB virtual disk
     - 1024 MB of memory
     - 32 MB of video memory
+    - These specifications are for a server-only distribution. For a distribution with a Desktop environment (GUI), assign 4 GB of RAM and 8 GB of storage.
 3. Installing a Linux distribution on the virtual machine with
     - user called `USERNAME` (if your GitLab name is `@musterm`, then `musterm`)
     - (host)name of the machine `USERNAMEvm` (e.g., `mustermvm`)
@@ -96,6 +97,8 @@ In the following subsections you will find additional instructions and explanati
 
 By default, [download Alpine Linux](https://alpinelinux.org/downloads/). [Ubuntu Server](https://ubuntu.com/download/server) is also fine.
 
+**Note:** If you are operating on an **ARM 64-bit architecture**, use **Ubuntu 25.10 (Desktop version)** or a later version, instead.
+
 #### 2. Creating the Virtual Machine
 
 While the installation image is downloading, you can already prepare the virtual machine.
@@ -164,6 +167,8 @@ Continue to step 5.
     - Install `neofetch` via `sudo apt update && sudo apt install -y neofetch`. This command will download and install `neofetch` using the package manager [`apt`](https://wiki.debian.org/Apt).
 - Clear the terminal using `clear` (or `Ctrl-L`) and run neofetch via by typing `neofetch` (or `fastfetch`) into the terminal and pressing `Enter`. It will show information about the Linux distribution version, available memory etc.
 
+**Note:** If you are running **Ubuntu Desktop on an ARM 64-bit architecture**, you may encounter an error when trying to install `neofetch` (e.g., `E: Unable to locate package`). In this case, you can use `fastfetch` as an alternative, which can be installed via `apt`.
+
 #### 5. Upload the Screenshot to SIM GitLab
 
 - Take a screenshot via VirtualBox. At the top of the VirtualBox window you find the menu item `View`. There you find the option `Take Screenshot (Host+E)`. Save the screenshot as `screenshot-virtualbox-USERNAME.png`.