Update README file according to VEBA v0.8 changes

[rguske]

Summary

PR will update the main README file according to changes which are going to be introduced in v0.8. Furthermore, deprecation information will be added to Event Router README.

Pull Request Checklist

🚨 Please review the guidelines for contributing to this repository.

• Please ensure that you are making a pull request against the Development branch
• Please use the WIP keyword in the title of your PR if you are not ready for review
• Please ensure that you have opened a Github Issue if you are resolving/fixing a problem
• Please ensure that you have signed all commits and that you have squashed all relevant commits related to your change
• Please make sure that you have tested your change locally by successfully building and deploying the VMware Event Broker Appliance and/or building and deploying VMware Event Router
• Please include any relevant screenshots and/or output as part of your testing
• Please include any documentation updates that is applicable for your changes

Change Type

What types of changes does your code introduce to the VMware Event Broker Appliance?

Put an x in all boxes that apply

Please check the type of change your PR introduces:

• Bugfix (non-breaking change which fixes an issue)
• Feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no api changes)
• Build related changes
• Documentation changes
• Other (please describe):

Resolved Issues

Closes: #1133

Testing Verification

• Verified locally

[lamw]

LGTM