uPowertoys: Dashboard Manager sorting + docs site

Repo: Jumoo/umbraco.community.powertoys

Dashboard Manager power toy: added drag-and-drop sorting of dashboards within each backoffice section, overriding the dashboard's registered manifest weight
Added a per-section "Reset order" button (only shown once that section has a custom order) to revert back to the dashboard's original registered order
Fixed the manager's default listing to sort by registered weight instead of alphabetically, so it matches the real on-screen dashboard order before any custom order is set
Opened PR #47
Tagged and published v17.0.0-rc2 on GitHub, triggering the release workflow to push to NuGet
Added a Jekyll docs site under docs/ for GitHub Pages: an overview page, install guide, and a page per power toy, with real screenshots from a running instance
Configured the docs site for a custom domain (powertoys.jumoo.co.uk) via a CNAME file and Jekyll url/baseurl config
Opened PR #48
Resolved a merge conflict in docs/CNAME after GitHub auto-committed its own CNAME file to v17/main when the custom domain was set in Pages settings