Update installing-cli.md (docker#2532)

Author: scjane

docker-cloud/installing-cli.md

@@ -115,7 +115,7 @@ $ export DOCKERCLOUD_NAMESPACE=myorganization
 ```
 
 You can also set the `DOCKERCLOUD_NAMESPACE` variable before each CLI command.
-for example:
+For example:
 
 ```none
 $ DOCKERCLOUD_NAMESPACE=myteam docker container ps