Populate changelog for 0.22.0 release

[ndgrigorian]

This PR populates the changelog for the 0.22.0 release

The updated changelog will be backported to master after

• Have you provided a meaningful PR description?
• Have you added a test, reproducer or referred to an issue with a reproducer?
• Have you tested your changes locally for CPU and GPU devices?
• Have you made sure that new changes do not introduce compiler warnings?
• Have you checked performance impact of proposed changes?
• Have you added documentation for your changes, if necessary?
• Have you added your changes to the changelog?
• If this PR is a work in progress, are you opening the PR as a draft?

[github-actions]

Deleted rendered PR docs from intelpython.github.com/dpctl, latest should be updated shortly. 🤞

[coveralls]

Coverage is 77.338% — update-changelog-0.22.0-release into maintenance/0.22.x. No base build found for maintenance/0.22.x.

[antonwolfy]

LGTM! Thank you @ndgrigorian