[enh] configurable default oscar style

searx/preferences.py

@@ -264,6 +264,7 @@ class Preferences(object):
                                                                                 'False': False,
                                                                                 'True': True}),
                                    'doi_resolver': MultipleChoiceSetting(['oadoi.org'], choices=DOI_RESOLVERS),
+                                   'oscar-style': EnumStringSetting(settings['ui'].get('theme_args', {}).get('oscar_style', 'logicodev'), choices=['', 'logicodev', 'logicodev-dark', 'pointhi']),
                                    }
 
         self.engines = EnginesSetting('engines', choices=engines)

searx/settings.yml

@@ -20,6 +20,8 @@ ui:
     templates_path : "" # Custom templates path - leave it blank if you didn't change
     default_theme : oscar # ui theme
     default_locale : "" # Default interface locale - leave blank to detect from browser information or use codes from the 'locales' config section
+    theme_args :
+        oscar_style : logicodev-dark # default style of oscar
 
 # searx supports result proxification using an external service: https://github.com/asciimoo/morty
 # uncomment below section if you have running morty proxy