win: fix Copilot by excluding r.bing.com #329

This commit modifies the blocking behavior of `r.bing.com` due to its
extensive use across multiple Windows features, including Copilot and
Maps. Previously, included in the 'Cortana and Live Tiles' block list,
this host was causing issues for Copilot functionalites, as noted in
issue #329. By excluding `r.bing.com` from block list, this update aims
to prevent unintended disruptions without compromising the privacy gains
of other scripts.

Changes include:

- Exclude `r.bing.com` from the "Cortana and Live Tiles" block list.
- Improve documentation to clarify the role and exclusions.
- Improve documentation with consistent header for blocked hosts.