Updates on cli reference documentation

- Update ps with `--last` flag
- Update commands with current output
- Make sure hugo does not detect the wrong language
- Update usage for `tag` command to be more coherent with the other ones

Signed-off-by: Vincent Demeester <vincent@sbr.pm>

docs/reference/commandline/kill.md

@@ -10,12 +10,15 @@ parent = "smn_cli"
 
 # kill
 
-    Usage: docker kill [OPTIONS] CONTAINER [CONTAINER...]
+```markdown
+Usage:  docker kill [OPTIONS] CONTAINER [CONTAINER...]
 
-    Kill a running container using SIGKILL or a specified signal
+Kill one or more running container
 
-      --help                 Print usage
-      -s, --signal="KILL"    Signal to send to the container
+Options:
+      --help            Print usage
+  -s, --signal string   Signal to send to the container (default "KILL")
+```
 
 The main process inside the container will be sent `SIGKILL`, or any
 signal specified with option `--signal`.