Add checkout.defaultRemote=origin

[salcode]

When I have more than one remotes and try to do something like

git switch feature/improve-visibility

where the branch feature/improve-visibility exists on the remote(s) but not on my local, I get a failure like the following.

hint: If you meant to check out a remote tracking branch on, e.g. 'origin',
hint: you can do so by fully qualifying the name with the --track option:
hint:
hint: git checkout --track origin/
hint:
hint: If you'd like to always have checkouts of an ambiguous prefer
hint: one remote, e.g. the 'origin' remote, consider setting
hint: checkout.defaultRemote=origin in your config.
fatal: 'feature/improve-visibility' matched multiple (2) remote tracking branches

It sounds like we can set this in our config. And since origin is almost always what we want, that should work well.

checkout.defaultRemote=origin

[salcode]

This is the line we could add to gitconfig

[checkout]
	defaultRemote=origin