Bug 27375: Set YAML file settings in .editorconfig

To test:
1) Start an editor that supports .editorconfig.
2) Open YAML file mappings.yaml for example.
3) Format the file.
4) Observe that nothing changes.

Sponsored-by: Koha-Suomi Oy

Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>

.editorconfig

@@ -13,3 +13,7 @@ charset = utf-8
 
 [*.json]
 indent_size = 2
+
+[*.yaml]
+indent_size = 2
+quote_type = single