This command creates an empty Git repository - basically a .git
directory with subdirectories for objects, refs/heads,
refs/tags, and template files. An initial branch without any
commits will be created (see the --initial-branch option below
for its name).
If the $GIT_DIR environment variable is set then it specifies a path
to use instead of ./.git for the base of the repository.
If the object storage directory is specified via the
$GIT_OBJECT_DIRECTORY environment variable then the sha1 directories
are created underneath; otherwise, the default $GIT_DIR/objects
directory is used.
Running git init in an existing repository is safe. It will not
overwrite things that are already there. The primary reason for
rerunning git init is to pick up newly added templates (or to move
the repository to another place if --separate-git-dir is given).