Update openrouter.mdx

Clarify that OpenRouter URL and app name are just for OpenRouter to track the most popular apps, and you can choose whatever you want here (but Open Interpreter is the most obvious choice)

Author: endolith

docs/language-models/hosted-models/openrouter.mdx

@@ -60,5 +60,5 @@ Set the following environment variables [(click here to learn how)](https://chat
 | Environment Variable  | Description  | Where to Find  |
 | --------------------- | ------------ | -------------- |
 | `OPENROUTER_API_KEY`       | The API key for authenticating to OpenRouter's services. | [OpenRouter Account Page](https://openrouter.ai/keys) |
-| `OR_SITE_URL`      | The site URL for OpenRouter's services. | [OpenRouter Account Page](https://openrouter.ai/keys) |
-| `OR_APP_NAME`   | The app name for OpenRouter's services. | [OpenRouter Account Page](https://openrouter.ai/keys) |
+| `OR_SITE_URL`      | An app URL for tracking usage, such as `https://github.com/openinterpreter/open-interpreter/`. | Your choice |
+| `OR_APP_NAME`   | An app name for tracking usage, such as "Open Interpreter". | Your choice |