docs: adding Mistral to docs as a provider (it is already a provider, just docs update) anomalyco#23070 (anomalyco#23072)

Author: jenperson

packages/web/src/content/docs/providers.mdx

@@ -1316,6 +1316,33 @@ To use Kimi K2 from Moonshot AI:
 
 ---
 
+### Mistral AI
+
+1.  Head over to the [Mistral AI console](https://console.mistral.ai/), create an account, and generate an API key.
+
+2. Run the `/connect` command and search for **Mistral AI**.
+
+   ```txt
+   /connect
+   ```
+
+3. Enter your Mistral API key.
+
+   ```txt
+   ┌ API key
+   │
+   │
+   └ enter
+   ```
+
+4. Run the `/models` command to select a model like _Mistral Medium_.
+
+   ```txt
+   /models
+   ```
+
+---
+
 ### Nebius Token Factory
 
 1. Head over to the [Nebius Token Factory console](https://tokenfactory.nebius.com/), create an account, and click **Add Key**.