text: Title: [FEATURE] Allow set Accept-Language
  Body: <!--
  DO NOT REQUEST UI/THEME/GUI/APPEARANCE IMPROVEMENTS HERE
  THESE SHOULD GO IN ISSUE #60
  REQUESTING A NEW FEATURE SHOULD BE STRICTLY RELATED TO NEW FUNCTIONALITY
  -->
  
  **Describe the feature you'd like to see added**
  Allow set `Accept-Language` in headers  in `Request.send`
  
  I encounter similar issue like https://github.com/benbusby/whoogle-search/issues/186#issuecomment-787468941
  
  Then I use `WHOOGLE_CONFIG_LANGUAGE` to set page's language to `lang_en` . However the date format is still Arabic like this `    21 Safar  1443 AH`  (the same as     September 29 2021) .
  
  so modified like this and it works.
  ```diff
  diff --git a/app/request.py b/app/request.py
  index 68e30d8..0a9a3e8 100644
  --- a/app/request.py
  +++ b/app/request.py
  @@ -157,6 +157,7 @@ class Request:
           self.language = (
               config.lang_search if config.lang_search else ''
           )
  +        self.lang_interface = config.lang_interface
           self.mobile = bool(normal_ua) and ('Android' in normal_ua
                                              or 'iPhone' in normal_ua)
           self.modified_user_agent = gen_user_agent(self.mobile)
  @@ -243,6 +244,9 @@ class Request:
               'User-Agent': modified_user_agent
           }
  
  +        if self.lang_interface:
  +            headers.update({'Accept-Language': self.lang_interface.replace('lang_', '') + ';q=1.0'})
  +
           # FIXME: Should investigate this further to ensure the consent
           # view is suppressed correctly
           now = datetime.now()
  ```
  
  so could there be some configs to let user choose if set "Accept-language" or not.
  
  