everyday: use the dashless form of git-init

The 'Everyday GIT' guide was using the old dashed form
of git-init.
Signed-off-by: NDavid Aguilar <davvid@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Documentation/everyday.txt

@@ -98,7 +98,7 @@ Use a tarball as a starting point for a new repository.::
 ------------
 $ tar zxf frotz.tar.gz
 $ cd frotz
-$ git-init
+$ git init
 $ git add . <1>
 $ git commit -m "import of frotz source tree."
 $ git tag v2.43 <2>