feat(docker): add searxng default settings config

新增searxng的docker配置文件settings.yml，配置基础运行参数、搜索格式、安全搜索等级与请求超时时间

docker/searxng/settings.yml

@@ -0,0 +1,11 @@
+use_default_settings: true
+server:
+  secret_key: "ultrasecretkey"
+  bind_address: "0.0.0.0"
+  limiter: false
+  image_proxy: false
+search:
+  formats: [html, json]
+  safe_search: 0
+outgoing:
+  request_timeout: 5