python/embed4all: use gguf model, allow passing kwargs/overriding model

gpt4all-bindings/python/gpt4all/gpt4all.py

@@ -30,17 +30,14 @@ class Embed4All:
     Python class that handles embeddings for GPT4All.
     """
 
-    def __init__(
+    def __init__(self, model_name: Optional[str] = None, n_threads: Optional[int] = None, **kwargs):
-        self,
-        n_threads: Optional[int] = None,
-    ):
         """
         Constructor
 
         Args:
             n_threads: number of CPU threads used by GPT4All. Default is None, then the number of threads are determined automatically.
         """
-        self.gpt4all = GPT4All(model_name='ggml-all-MiniLM-L6-v2-f16.bin', n_threads=n_threads)
+        self.gpt4all = GPT4All(model_name or 'ggml-all-MiniLM-L6-v2-f16.gguf', n_threads=n_threads, **kwargs)
 
     def embed(self, text: str) -> List[float]:
         """
@@ -315,7 +312,6 @@ class GPT4All:
             callback: pyllmodel.ResponseCallbackType,
             output_collector: List[MessageType],
         ) -> pyllmodel.ResponseCallbackType:
-
             def _callback(token_id: int, response: str) -> bool:
                 nonlocal callback, output_collector