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

pages/common/runsvdir.md

@@ -0,0 +1,16 @@
+# runsvdir
+
+> Run an entire directory of services.
+> More information: <https://manpages.ubuntu.com/manpages/latest/man8/runsvdir.8.html>.
+
+- Start and manage all services in a directory as the current user:
+
+`runsvdir {{path/to/services}}`
+
+- Start and manage all services in a directory as root:
+
+`sudo runsvdir {{path/to/services}}`
+
+- Start services in separate sessions:
+
+`runsvdir -P {{path/to/services}}`