docs: mark version and prefix optional in VersionedAPISchema (#1934)

**Description**

Since they have "omitempty" tag they should be optional
This is a bit confusing as it is now

Signed-off-by: Mikhail Toldov <matoldov@gmail.com>
Co-authored-by: Ignasi Barrera <ignasi@tetrate.io>

Author: herewasmike

api/v1alpha1/shared_types.go

@@ -27,6 +27,7 @@ type VersionedAPISchema struct {
 	// prefix field. This is to maintain backward compatibility. This will be removed in future releases.
 	//
 	// See https://aigateway.envoyproxy.io/docs/capabilities/llm-integrations/supported-providers for details.
+	// +optional
 	Version *string `json:"version,omitempty"`
 
 	// Prefix is the prefix for the API.
@@ -41,6 +42,7 @@ type VersionedAPISchema struct {
 	// use prefix, so you can leave this field unset.
 	//
 	// See https://aigateway.envoyproxy.io/docs/capabilities/llm-integrations/supported-providers for details.
+	// +optional
 	Prefix *string `json:"prefix,omitempty"`
 }
 

site/docs/api/api.mdx

@@ -2524,12 +2524,12 @@ the ai-gateway, but by the vendor via proper versioning.
 /><ApiField
   name="version"
   type="string"
-  required="true"
+  required="false"
   description="Version is the version of the API schema.<br />When the name is set to AzureOpenAI, this version maps to `API Version` in the<br />Azure OpenAI API documentation (https://learn.microsoft.com/en-us/azure/ai-services/openai/reference#rest-api-versioning).<br />**Deprecated Behavior**: When the name is set to `OpenAI`, this version field will behave as the<br />prefix field. This is to maintain backward compatibility. This will be removed in future releases.<br />See https://aigateway.envoyproxy.io/docs/capabilities/llm-integrations/supported-providers for details."
 /><ApiField
   name="prefix"
   type="string"
-  required="true"
+  required="false"
   description="Prefix is the prefix for the API.<br />When the name is set to `OpenAI`, `chat completions` API endpoint will be `$\{this_field\}/chat/completions`.<br />It can be with or without a leading slash (`/`).<br />This is especially useful when routing to the backend that has an OpenAI compatible API but has a different<br />prefix. For example, Gemini OpenAI compatible API (https://ai.google.dev/gemini-api/docs/openai) uses<br />`/v1beta/openai` prefix. Another example is that Cohere AI (https://docs.cohere.com/v2/docs/compatibility-api)<br />uses `/compatibility/v1` prefix. On the other hand, DeepSeek (https://api-docs.deepseek.com/) doesn't<br />use prefix, so you can leave this field unset.<br />See https://aigateway.envoyproxy.io/docs/capabilities/llm-integrations/supported-providers for details."
 />