add styleci config (copied from core)

.styleci.yml

@@ -0,0 +1,29 @@
+preset: symfony
+
+enabled:
+
+disabled:
+  - concat_without_spaces
+  - multiline_array_trailing_comma
+  - single_quote
+  - unalign_double_arrow
+  - phpdoc_no_package
+  - phpdoc_summary
+  - phpdoc_no_empty_return
+  - phpdoc_scalar
+  - phpdoc_separation 
+  - unalign_equals
+  - spaces_cast
+  - no_empty_lines_after_phpdocs
+  - phpdoc_to_comment
+  - phpdoc_align
+  - empty_return
+  - pre_increment
+  - phpdoc_type_to_var
+
+finder:
+  exclude:
+    - "src/javascript"
+    - "src/lib/legacy/idn"
+    - "tools"
+    - "src/system/RoutesModule"