[mod] add hotkeys option to settings.yml

The change in the hotkey mechanism introduced in 317db5b04 does not allow
configuration via `settings.yml`.  This commit adds that functionality.

Closes: #2898

docs/admin/settings/settings_ui.rst

@@ -20,6 +20,7 @@
      theme_args:
        simple_style: auto
      search_on_category_select: true
+     hotkeys: default
 
 .. _static_use_hash:
 
@@ -64,3 +65,6 @@
 
 ``search_on_category_select``:
   Perform search immediately if a category selected. Disable to select multiple categories.
+
+``hotkeys``:
+  Hotkeys to use in the search interface: ``default``, ``vim`` (Vim-like).

searx/preferences.py

@@ -466,7 +466,7 @@ class Preferences:
                 locked=is_locked('search_on_category_select')
             ),
             'hotkeys': EnumStringSetting(
-                'default',
+                settings['ui']['hotkeys'],
                 choices=['default', 'vim']
             ),
             # fmt: on

searx/settings.yml

@@ -127,6 +127,8 @@ ui:
   # Perform search immediately if a category selected.
   # Disable to select multiple categories at once and start the search manually.
   search_on_category_select: true
+  # Hotkeys: default or vim
+  hotkeys: default
 
 # Lock arbitrary settings on the preferences page.  To find the ID of the user
 # setting you want to lock, check the ID of the form on the page "preferences".

searx/settings_defaults.py

@@ -201,6 +201,7 @@ SCHEMA = {
         'infinite_scroll': SettingsValue(bool, False),
         'cache_url': SettingsValue(str, 'https://web.archive.org/web/'),
         'search_on_category_select': SettingsValue(bool, True),
+        'hotkeys': SettingsValue(('default', 'vim'), 'default'),
     },
     'preferences': {
         'lock': SettingsValue(list, []),