runit, runsv, runsvdir, runsvchdir, sv: add more information link and move to common/ (#5648)

pages/common/sv.md

@@ -0,0 +1,16 @@
+# sv
+
+> Control a running runsv service.
+> More information: <https://manpages.ubuntu.com/manpages/latest/man8/sv.8.html>.
+
+- Start a service:
+
+`sudo sv up {{path/to/service}}`
+
+- Stop a service:
+
+`sudo sv down {{path/to/service}}`
+
+- Get service status:
+
+`sudo sv status {{path/to/service}}`