Update define-command-argument-container.md

use uppercase letter in not and add args corresponding description

fix grammatical

Author: city2011

content/en/docs/tasks/inject-data-application/define-command-argument-container.md

@@ -36,7 +36,7 @@ If you define args, but do not define a command, the default command is used
 with your new arguments.
 
 {{< note >}}
-The `command` field corresponds to `entrypoint` in some container runtimes.
+The `command` field corresponds to `ENTRYPOINT`, and the `args` field corresponds to `CMD` in some container runtimes.
 {{< /note >}}
 
 In this exercise, you create a Pod that runs one container. The configuration