Delete forks with unmerged PRs

[garyking]

It seems like this script won't ask to delete my forks that have PRs that were closed but not merged.

Please allow an option to show forks that have closed PRs and weren't merged, rather than just forks that have closed PRs that were merged.

[waldyrious]

Just chiming in to suggest that such an option should be toggled off by default, so that the tool doesn't encourage destructive actions which could happen if the user misses that detail or assumes the tool is always safe by design, given the description in the README: "if there’s any commits in the fork that have not yet been merged upstream, the fork will be kept, of course."