[enh] Add preference section to two upstream plugins for simple theme integration

searx/plugins/open_results_on_new_tab.py

@@ -20,5 +20,6 @@ description = gettext('Results are opened in the same window by default. '
                       'This plugin overwrites the default behaviour to open links on new tabs/windows. '
                       '(JavaScript required)')
 default_on = False
+preference_section = 'ui'
 
 js_dependencies = ('plugins/js/open_results_on_new_tab.js',)

searx/plugins/vim_hotkeys.py

@@ -5,6 +5,7 @@ description = gettext('Navigate search results with Vim-like hotkeys '
                       '(JavaScript required). '
                       'Press "h" key on main or result page to get help.')
 default_on = False
+preference_section = 'ui'
 
 js_dependencies = ('plugins/js/vim_hotkeys.js',)
 css_dependencies = ('plugins/css/vim_hotkeys.css',)