systemd-socket-activate: add page (#11221)

* systemd-socket-activate:  add page

---------

Co-authored-by: K.B.Dharun Krishna <kbdharunkrishna@gmail.com>

pages/linux/systemd-socket-activate.md

@@ -0,0 +1,24 @@
+# systemd-socket-activate
+
+> Socket activation for systemd services.
+> More information: <https://www.freedesktop.org/software/systemd/man/latest/systemd-socket-activate.html>.
+
+- Activate a service when a specific socket is connected:
+
+`systemd-socket-activate {{path/to/socket.service}}`
+
+- Activate multiple sockets for a service:
+
+`systemd-socket-activate {{path/to/socket1.service}} {{path/to/socket2.service}}`
+
+- Pass environment variables to the service being activated:
+
+`{{SYSTEMD_SOCKET_ACTIVATION=1}} systemd-socket-activate {{path/to/socket.service}}`
+
+- Activate a service along with a notification socket:
+
+`systemd-socket-activate {{path/to/socket.socket}} {{path/to/service.service}}`
+
+- Activate a service with a specified port:
+
+`systemd-socket-activate {{path/to/socket.service}} -l {{8080}}`