Many developers already use
Visual Studio Code,
which is a small and distinct program from Visual Studio available for Linux, MacOS and Windows.
Currently, VS Code isn’t capable of 3-way merge, so look to Meld for
Configure Visual Studio Code for Git
Use VS Code for Git difftool by adding to ~/.gitconfig:
[diff] tool = vscode [difftool "vscode"] cmd = code --wait --diff $LOCAL $REMOTE