add doc strings

main.py

@@ -15,14 +15,30 @@
 
 
 @app.get("/")
-def root():
+def root() -> dict:
+    """
+    This function works from root 
+    and demonstrates welcome message.
+
+    Returns:
+        dict: Welcome message
+    """
     return {"message": "Hello World"}
 
 
 @app.post("/predict/")
 # функция для расчета модели,
 # в "input" передаются текст
-def predict(input: dict):
+def predict(input: dict) -> dict:
+    """
+    This function predicts 
+
+    Args:
+        input (dict): dict with text for prediction
+    
+    Returns:
+        dict: dict with the prediction of text sentiment
+    """
     inputs = tokenizer(
         input["text"],
         max_length=512,