Splitting out the cli command into parts.

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

docs/reference/commandline/kill.md

@@ -0,0 +1,21 @@
+<!--[metadata]>
++++
+title = "kill"
+description = "The kill command description and usage"
+keywords = ["container, kill, signal"]
+[menu.main]
+parent = "smn_cli"
+weight=1
++++
+<![end-metadata]-->
+
+# kill
+
+    Usage: docker kill [OPTIONS] CONTAINER [CONTAINER...]
+
+    Kill a running container using SIGKILL or a specified signal
+
+      -s, --signal="KILL"    Signal to send to the container
+
+The main process inside the container will be sent `SIGKILL`, or any
+signal specified with option `--signal`.