This PR will add customhelp section in `kompose up --help` section,
which will show consistency in help section.
Issue reference: #842
for example,
```
$ kompose up --help
Deploy your Dockerized application to a container orchestrator. (default "kubernetes")
Usage:
kompose up [flags]
OpenShift Flags:
--build-branch Specify repository branch to use for buildconfig (default is current branch name)
--build-repo Specify source repository for buildconfig (default is current branch's remote url
--insecure-repository Specify to use insecure docker repository while generating Openshift image stream object
Flags:
--build string Set the type of build ("local"|"build-config" (OpenShift only)|"none") (default "local")
-h, --help help for up
--namespace string Specify Namespace to deploy your application (default "default")
--replicas int Specify the number of replicas generated (default 1)
--volumes string Volumes to be generated ("persistentVolumeClaim"|"emptyDir") (default "persistentVolumeClaim")
Global Flags:
--error-on-warning Treat any warning as an error
-f, --file stringArray Specify an alternative compose file
--provider string Specify a provider. Kubernetes or OpenShift. (default "kubernetes")
--suppress-warnings Suppress all warnings
-v, --verbose verbose output
```