Resolve a pull request review thread with:
vk resolve https://github.com/leynos/vk/pull/191#discussion_r123456789
The resolver uses GitHub GraphQL. When vk is built with the
unstable-rest-resolve feature, -m or --message posts a reply before
resolving:
vk resolve https://github.com/leynos/vk/pull/191#discussion_r123456789 \
--message "Addressed in the latest commit."
If the reply fails, the command stops before resolving the thread.