ghq change origin

Summary

This issue proposes adding a new `ghq change` command that allows users to update the remote origin of a local Git repository managed by ghq. This would involve parsing the command arguments, finding the specified repository, and then executing the appropriate Git command to change its remote URL.

Skills Required

Go programming languageGit command-line operationsCommand-line argument parsingError handling

Files Likely Touched

cmd/ghq/main.go
cmd/ghq/change.go
repository/repository.go
git/git.go