Revise Ubuntu installation instructions for LTS versions

Updated installation instructions for Ubuntu to include support for version 26.04 LTS and clarified support status for older versions.

Author: jullrich

docs/install-instructions/Ubuntu.md

@@ -1,7 +1,7 @@
-Installing on Ubuntu Server 24.04 LTS
-=====================================
+Installing on Ubuntu Server 24.04 LTS and 26.04 LTS
+===================================================
 
-Note: Ubuntu Server 22.04 LTS is no longer supported.
+Note: Ubuntu server versions 22.04 LTS and older are no longer supported.
 
 **Via ISO Image**
 Install the default version Ubuntu Server 24.04 LTS. Don't select any additional packages when prompted. During installation, create a user called "dshield."
@@ -15,7 +15,14 @@ sudo adduser --disabled-password --gecos "DShield Honeypot" dshield
 sudo adduser dshield sudo
 ```
 
-If you installed the "minimum server": Make sure to install the editor of your choice. (for example, "sudo apt install emacs-nox")
+If you installed the "minimum server": Make sure to install the editor of your choice. (for example, "sudo apt install emacs-nox").
+
+**Optional: sudo without passwords
+The "adduser" command does not configure a password for the dshield user. However, the user must have the abilitiy to use sudo. Either add a password for the "dshield" account, or modify the /etc/sudoers file:
+
+```
+
+```
 
 **After Completing Installation**
 Upgrade the base system and ensure git and openssh-server are already installed: