I use Yury Zhauniarovich's blog as reference. I modify his commands and remove the --new-window flag.
Set VS code as default editor:
git config --global core.editor "code --wait"
Check to make sure it's set and to add more settings:
git config --global -e
Where you can enter the settings below:
[core]
editor = code --wait
[merge]
tool = vscode
[mergetool "vscode"]
cmd = code --wait $MERGED
[diff]
tool = vscode
[difftool "vscode"]
cmd = code --wait --diff $LOCAL $REMOTE