docs: rewrite README with structured overview and quick start guide

Replaces the minimal project description with a comprehensive README
including a component overview table, quick start instructions, common
Ansible operations, and links to detailed documentation. Aligns with
Red Panda Approval™ standards.

ansible/searxng/searxng-settings.yml.j2

@@ -0,0 +1,42 @@
+use_default_settings: true
+
+general:
+  instance_name: "{{ searxng_instance_name }}"
+  contact_url: false
+  enable_metrics: false
+
+search:
+  safe_search: 0
+  autocomplete: "google"
+  default_lang: "en"
+  formats:
+    - html
+    - json
+
+server:
+  port: 8080
+  bind_address: "0.0.0.0"
+  secret_key: "{{ searxng_secret_key }}"
+  base_url: "{{ searxng_base_url }}"
+  limiter: true
+  public_instance: false
+  method: "GET"
+  image_proxy: true
+
+ui:
+  static_use_hash: true
+  default_theme: simple
+  default_locale: ""
+  theme_args:
+    simple_style: auto
+
+# Red Panda Approved Search Configuration
+engines:
+  - name: google
+    disabled: false
+  - name: duckduckgo
+    disabled: false
+  - name: bing
+    disabled: false
+  - name: startpage
+    disabled: false