Missing info from manual install doc

[ANOka79]

I think this is missing from Manual Install.
(On Ubuntu) Start Scrutiny Webapp paragraph.

Scrutiny as service

Create a new file for service into /lib/systemd/system/scrutiny.service (example)

# /lib/systemd/system/scrutiny.service

[Unit]
Description=Scrutiny Web

[Service]
Directory=/opt/scrutiny/bin
ExecStart=/opt/scrutiny/bin/scrutiny-web-linux-amd64 start --config /opt/scrutiny/config/scrutiny.yaml --log-file /tmp/scrutiny_web.log
Type=simple
TimeoutStopSec=10
Restart=on-failure
RestartSec=5

[Install]
WantedBy=multi-user.target
Alias=scrutiny.service

Make symlink

sudo ln -s /lib/systemd/system/scrutiny.service /etc/systemd/system/scrutiny.service

Start service

sudo systemctl daemon-reload
sudo systemctl start scrutiny

[Porco-Rosso]

in order to 'enable' the service to start on reboot I found you need to just use:
systemctl enable /lib/systemd/system/scrutiny.service

This will automatically create the symlink, otherwise debian will give the warning: Failed to enable unit: Refusing to operate on alias name or linked unit file: scrutiny.service

[AnalogJ]

Hey @Porco-Rosso @ANOka79 can you open a PR to update the docs? I'd be happy to merge it

[Porco-Rosso]

I'll give it a shot when I find time. But if anyone else wants to do it sooner, please feel free.