Enhancement: return code relevant to the OS llm is operating on

[chillmanAU]

By default llm cmd generates code specific to Linux. For example:
llm cmd show list of system users
returns
cat /etc/passwd
regards of OS, whereas
llm cmd show list of system users on windows
returns
net user

It would be good if the OS was detected by llm cmd and the code returned was specific to the OS without the need to specify the OS in the command