Update manual upgrade page with better order of operations

[dereknola]

Addresses: #178

Mentions that you have to stop the existing K3s service before running the installation script with a new version.

[brandond]

have to stop the existing K3s service before running the installation script with a new version

Do you though? I thought that the install script would restart the service for you if the config or version changed.

[dereknola]

Ah I guess your right. My brain was just on autopilot when looking at the install script output:

[INFO]  Creating killall script /usr/local/bin/k3s-killall.sh
[INFO]  Creating uninstall script /usr/local/bin/k3s-uninstall.sh
[INFO]  env: Creating environment file /etc/systemd/system/k3s.service.env
[INFO]  systemd: Creating service file /etc/systemd/system/k3s.service
[INFO]  systemd: Enabling k3s unit
Created symlink /etc/systemd/system/multi-user.target.wants/k3s.service → /etc/systemd/system/k3s.service.
[INFO]  systemd: Starting k3s

We weirdly don't have output that the old k3s service was stopped.

[brandond]

It's because we just log that we start it when actually we restart it. Which is either a start or a stop/start depending on current state.
https://github.com/k3s-io/k3s/blob/bba3e3c66b22bbf112dc316a9b5dbd27f68f4ba8/install.sh#L1042-L1045