New Boards Hub, Sprint 216 update

This post details bug fixes and progress updates for the New Boards Hub across two sprints (215 and 216). It highlights the rollout of the 'Try the New Boards Hub' message to more customers, moving it closer to becoming the default experience. The majority of the content consists of a list of specific bugs fixed, covering issues with sprint backlogs, shortcuts, work item creation and editing, UI elements in dark mode, extensibility points, templates, attachments, styles, and more.