chore: separate install docs (#3859)

docs/install/packages.md

@@ -0,0 +1,42 @@
+Coder publishes the following system packages [in GitHub releases](https://github.com/coder/coder/releases):
+
+- .deb (Debian, Ubuntu)
+- .rpm (Fedora, CentOS, RHEL, SUSE)
+- .apk (Alpine)
+
+Once installed, you can run Coder as a system service.
+
+```sh
+# Set up an access URL or enable CODER_TUNNEL
+sudo vim /etc/coder.d/coder.env
+
+# To systemd to start Coder now and on reboot
+sudo systemctl enable --now coder
+
+# View the logs to see Coder's URL and ensure a successful start
+journalctl -u coder.service -b
+```
+
+> Set `CODER_ACCESS_URL` to the external URL that users and workspaces will use to
+> connect to Coder. This is not required if you are using the tunnel. Learn more
+> about Coder's [configuration options](../admin/configure.md).
+
+Visit the Coder URL in the logs to set up your first account, or use the CLI:
+
+```sh
+coder login <access-url>
+```
+
+## Restarting Coder
+
+After updating Coder or applying configuration changes, restart the server:
+
+```sh
+sudo systemctl restart coder
+```
+
+## Next steps
+
+- [Quickstart](../quickstart.md)
+- [Configuring Coder](../admin/configure.md)
+- [Templates](../templates.md)