v0.18.0

wtm checkout replaces the pr group.

Breaking

• wtm pr checkout is now wtm checkout: update scripts and aliases.
• wtm pr list is removed: use wtm list --with-prs or the checkout wizard.

Added

• wtm checkout [number] creates a worktree from a pull request; without a number, a wizard lists open PRs.
• --review, --mine, --from and --env-from filter PRs and preset the wizard's answers.