Use "init" as directory index

The docs mentioned 'init' (which is consistent with Salt and Python), but
somehow I made that 'index' in the code.

Signed-off-by: martin f. krafft <madduck@madduck.net>
diff --git a/reclass/storage/yaml_fs/__init__.py b/reclass/storage/yaml_fs/__init__.py
index fafc033..ae614e0 100644
--- a/reclass/storage/yaml_fs/__init__.py
+++ b/reclass/storage/yaml_fs/__init__.py
@@ -36,7 +36,11 @@
             if relpath == '.':
                 return name
             parts = relpath.split(os.path.sep)
-            if name != 'index':
+            if name != 'init':
+                # "init" is the directory index, so only append the basename
+                # to the path parts for all other filenames. This has the
+                # effect that data in file "foo/init.yml" will be registered
+                # as data for class "foo", not "foo.init"
                 parts.append(name)
             return '.'.join(parts)
         self._classes_uri = classes_uri