Modify introductory paragraph of Cloud guides

[NimG98]

Based off of review feedback, the introduction of the cloud guides has been modified. The rest of the cloud guides should be updated for consistency.

Change the following paragraph:

There are different cloud-based solutions for running your workloads in a Kubernetes cluster. A cloud-based infrastructure enables you to focus on developing your microservices without worrying about details related to the servers you deploy them to. Using a cloud helps you to easily scale and serve your microservices in a high-availability setup.

To:

There are different cloud-based solutions for running your Kubernetes workloads. A cloud-based infrastructure enables you to focus on developing your microservices without worrying about low-level infrastructure details for deployment. Using a cloud helps you to easily scale and manage your microservices in a high-availability setup.

Guides to change:

• [x] cloud-ibm
• [x] cloud-aws
• [x] cloud-azure
• [x] cloud-openshift

[justineechen]

Updated cloud-ibm, cloud-azure, cloud-openshift on docker-update branches

[NimG98]

For guide-cloud-aws: https://github.com/OpenLiberty/guide-cloud-aws/pull/61