Added git check

[jjasghar]

You can't always assume people have git installed 🤘

[crash5]

If I'm right with this patch you cant use the script without git. Which is not desirable in my opinion.

Is the check on

vimv/vimv

Line 35 in 3bb51a4

if git ls-files --error-unmatch "${src[i]}" > /dev/null 2>&1; then

is not enough?