add reka core model (vision)

etc/examples/image_chat_reka.py

@@ -0,0 +1,27 @@
+# Image Chat with Reca
+# !! YOU NEED COOKIES / BE LOGGED IN TO chat.reka.ai
+# download an image and save it as test.png in the same folder
+
+from g4f.client import Client
+from g4f.Provider import Reka
+
+client = Client(
+    provider = Reka # Optional if you set model name to reka-core
+)
+
+completion = client.chat.completions.create(
+    model = "reka-core",
+    messages = [
+        {
+            "role": "user",
+            "content": "What can you see in the image ?"
+        }
+    ],
+    stream = True,
+    image = open("test.png", "rb") # open("path", "rb"), do not use .read(), etc. it must be a file object
+)
+
+for message in completion:
+    print(message.choices[0].delta.content or "")
+    
+    # >>> In the image there is ...