feat:add user llm config

metagpt/config2.py

@@ -99,7 +99,20 @@ class Config(CLIParams, YamlModel):
         dicts += [Config.read_yaml(path) for path in default_config_paths]
         final = merge_dict(dicts)
         return Config(**final)
-
+    
+    @classmethod
+    def config(cls,config:dict):
+        """user config llm
+        example:
+        llm_config = {"llm": {"api_type": "xxx", "api_key": "xxx", "model": "xxx"}
+        gpt4 = Config.config(llm_config)
+        A = Role(name="A", profile="Democratic candidate", goal="Win the election", actions=[a1], watch=[a2], config=gpt4)
+        """
+        dicts = [dict(os.environ)]
+        dicts += [config]
+        final = merge_dict(dicts)
+        return Config(**final)
+    
     def update_via_cli(self, project_path, project_name, inc, reqa_file, max_auto_summarize_code):
         """update config via cli"""