Support not stripping ".git" from directory name

[hendursaga]

While trying to setup git-link for a cgit-powered repository (https://git.adrian.geek.nz/rhapsode.git), it wouldn't work, because https://github.com/sshaw/git-link/blob/master/git-link.el#L412-L414 strips ".git" from the directory name. As a workaround, I currently do something similar to git-link-savannah where I pass a modified dirname variable.