docs(reliability.md): add content policy fallback docs to proxy

docs/my-website/docs/proxy/reliability.md

@@ -409,6 +409,28 @@ print(response)
 </Tabs>
 
 
+### Content Policy Fallbacks
+
+Fallback across providers (e.g. from Azure OpenAI to Anthropic) if you hit content policy violation errors. 
+
+```yaml
+model_list:
+	- model_name: gpt-3.5-turbo-small
+	  litellm_params:
+		model: azure/chatgpt-v-2
+        api_base: os.environ/AZURE_API_BASE
+        api_key: os.environ/AZURE_API_KEY
+        api_version: "2023-07-01-preview"
+
+    - model_name: claude-opus
+      litellm_params:
+        model: claude-3-opus-20240229
+        api_key: os.environ/ANTHROPIC_API_KEY
+
+litellm_settings:
+  content_policy_fallbacks: [{"gpt-3.5-turbo-small": ["claude-opus"]}]
+```
+
 ### EU-Region Filtering (Pre-Call Checks)
 
 **Before call is made** check if a call is within model context window with  **`enable_pre_call_checks: true`**.