chore: update

README.md

@@ -258,6 +258,12 @@ English | [简体中文](https://github.com/Deeptrain-Community/chatnio/blob/mas
     - Normally, the backend is open to cross-origin requests for all domains. There is no need to enable strict cross-origin detection if there is no specific requirement.
     - If strict cross-origin detection needs to be enabled, it can be configured in the backend environment variable and `ALLOW_ORIGINS`, such as `ALLOW_ORIGINS=chatnio.net,chatnio.app` (no protocol prefix is required, and www parsing does not need to be added manually, The backend will automatically identify and allow cross-domain). In this way, strict cross-origin detection will be supported (such as *http://www.chatnio.app*, *https://chatnio.net* will be allowed, and other domains will be rejected).
     - Even when strict cross-origin detection is enabled, /v1 interface will still allow cross-origin requests from all domains to ensure normal use of the transfer API.
+16. **How is the model mapping feature used?**
+    - Model mappings within a channel are in the format `[from]>[to]`, with line breaks between mappings, **from** is the model requested, **to** is the model actually sent upstream and needs to be actually supported by the upstream.
+    - e.g. I have a reverse channel, fill in `gpt-4-all>gpt-4`, then when my user requests a **gpt-4-all** model from that channel, the backend will model map to **gpt-4** to request **gpt-4** from that channel, which supports 2 models, **gpt-4** and **gpt-4-all** (essentially both **gpt-4** and **gpt-4-all**). Both are essentially **gpt-4**).
+    - If I don't want my reverse channel to affect the **gpt-4** channel group, I can prefix it with `!gpt-4-all>gpt-4`, and the channel **gpt-4** will be ignored, and the channel will only support 1 model, **gpt-4-all** (but is essentially **gpt-4**).
+
+Translated with DeepL.com (free version)
 ## 📦 Technology Stack
 - Frontend: React + Radix UI + Tailwind CSS + Shadcn + Tremor + Redux
 - Backend: Golang + Gin + Redis + MySQL