Update release notes on website / in editor

[cwebster-99]

We want to reconsider our release notes approach so that it is easier to obtain information on product changes and features. This experience can be broken down into our in-product release notes shown on update and the release notes published on the website

Related microsoft/vscode#251384 and https://github.com/microsoft/vscode-copilot/issues/16320 (internal)

[ntrogh]

Did a quick vibe coding experiment to add tags and filtering to the release notes (currently only web experience).

release-notes-filters-optimized.mp4