Splitting out the cli command into parts.

Signed-off-by: Mary Anthony <mary@docker.com>

docs/reference/commandline/pause.md

@@ -0,0 +1,27 @@
+<!--[metadata]>
++++
+title = "pause"
+description = "The pause command description and usage"
+keywords = ["cgroups, container, suspend, SIGSTOP"]
+[menu.main]
+parent = "smn_cli"
+weight=1
++++
+<![end-metadata]-->
+
+# pause
+
+    Usage: docker pause CONTAINER [CONTAINER...]
+
+    Pause all processes within a container
+
+The `docker pause` command uses the cgroups freezer to suspend all processes in
+a container. Traditionally, when suspending a process the `SIGSTOP` signal is
+used, which is observable by the process being suspended. With the cgroups freezer
+the process is unaware, and unable to capture, that it is being suspended,
+and subsequently resumed.
+
+See the
+[cgroups freezer documentation](https://www.kernel.org/doc/Documentation/cgroups/freezer-subsystem.txt)
+for further details.
+