docs: PE-7904 Add TUI network settings limitation (#8972)

* Add TUI network settings limitation

* ci: auto-formatting prettier issues

* Update docs/docs-content/clusters/edge/site-deployment/site-installation/initial-setup.md

Co-authored-by: Amanda Churi Filanowski <[email protected]>

* ci: auto-formatting prettier issues

---------

Co-authored-by: svetlana-efimova <[email protected]>
Co-authored-by: Amanda Churi Filanowski <[email protected]>

Author: svetlana-efimova

docs/docs-content/clusters/edge/site-deployment/site-installation/initial-setup.md

@@ -28,6 +28,10 @@ automatically. To launch the setup manually, issue the command `/opt/spectroclou
 - Depending on the console environment, the TUI may not display the full QR code for Palette registration. This issue
   has been observed in the VMware vSphere web console, where limited console window size can cause the QR code to appear
   partially truncated.
+- In Agent mode, modifying VLAN settings using the TUI is allowed only if the settings were created via the TUI.
+  Pre-existing settings are read-only. If you attempt to update pre-existing network settings via the TUI, a new
+  configuration is created alongside the existing one. To manage pre-existing configurations, use the original
+  configuration method such as `systemd-networkd`, Netplan, or NetworkManager.
 
 ## Prerequisites