Add CHANGELOG for v1.11.1

[AkshaySainiDell]

Description

Add changelog of CSM v1.11.1 release

GitHub Issues

List the GitHub issues impacted by this PR:

GitHub Issue #
https://github.com/dell/csm/issues/1478

Checklist:

• [x] I have performed a self-review of my own code to ensure there are no formatting, vetting, linting, or security issues
• [ ] I have verified that new and existing unit tests pass locally with my changes
• [ ] I have not allowed coverage numbers to degenerate
• [ ] I have maintained at least 90% code coverage
• [ ] I have commented my code, particularly in hard-to-understand areas
• [x] I have made corresponding changes to the documentation
• [ ] I have added tests that prove my fix is effective or that my feature works
• [ ] I have maintained backward compatibility

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Please also list any relevant details for your test configuration

• [ ] Test A
• [ ] Test B

[csmbot]

@AkshaySainiDell: Thank you for submitting your pull request!

Please make sure you have followed our contributing guidelines. We will review it as soon as possible.

---

We want your feedback! If you have any questions or suggestions regarding our contributing process/workflow, please reach out to us at container.storage.modules@dell.com.