t0001: test git init when run via an alias

t0001: test git init when run via an alias

Add some tests to document the correct behavior of (possibly aliased)
init when run within and outside a git directory.

If I set up a simple git alias “quietinit = init --quiet”, usually it
will work just like ‘git init --quiet’.

There are some differences, unfortunately, since in the process of
checking for aliases, git has to look for a .git/config file.  If ‘git
quietinit’ is run from a subdirectory of an existing git repository,
that repository’s configuration will affect the configuration of the
new repository.  In particular, the new repository can inherit
bogus values for core.bare and core.worktree.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>