Fetch server_url from env

.env.sample

@@ -1,3 +1,4 @@
 ANTHROPIC_API_KEY=""
 GROQ_API_KEY=""
 OPENAI_API_KEY=""
+OLLAMA_API_URL="http://localhost:11434"

aimodels/providers/ollama_interface.py

@@ -2,14 +2,17 @@
 
 from aimodels.framework import ProviderInterface, ChatCompletionResponse
 from httpx import ConnectError
+import os
 
 
 class OllamaInterface(ProviderInterface):
     """Implements the ProviderInterface for interacting with the Ollama API."""
 
     _OLLAMA_STATUS_ERROR_MESSAGE = "Ollama is likely not running. Start Ollama by running `ollama serve` on your host."
 
-    def __init__(self, server_url="http://localhost:11434"):
+    def __init__(
+        self, server_url=os.getenv("OLLAMA_API_URL", "http://localhost:11434")
+    ):
         """Set up the Ollama API client with the key from the user's environment."""
         from ollama import Client