expand leading tilde in GH_CONFIG path to $HOME

[wilmoore]

Environment

export GH_CONFIG="~/.private/config/gh/config"

Command

% gh checkout https://github.com/user/repo/pull/34

Expected Result

Branch user-branchname set up to track remote branch branchname from user.

Actual Result

Before Change

github.com password for wilmoore (never stored):

After Change

Branch user-branchname set up to track remote branch branchname from user.