Describe the feature or problem you’d like to solve

gh alias command provides a delete subcommand. Users can delete alias one by one. If they wanna delete only one alias, it is no problem. But I can assume that there is a need to delete all registered aliases and reset them. In such cases, I feel that the existing functionality is not sufficient.

Proposed solution

I propose to add --all flag to gh alias delete command to delete all registered aliases.

$ gh alias list
t1: help
t2: help
$ gh alias delete --all
✓ Deleted alias t1; was help
✓ Deleted alias t2; was help
$ gh alias list
$