[tokenizers] Updates data processors, docstring, examples and model cards to the new API (#5308)

* remove references to old API in docstring - update data processors

* style

* fix tests - better type checking error messages

* better type checking

* include awesome fix by @LysandreJik for #5310

* updated doc and examples

examples/multiple-choice/utils_multiple_choice.py

@@ -510,12 +510,13 @@ def convert_examples_to_features(
             else:
                 text_b = example.question + " " + ending
 
-            inputs = tokenizer.encode_plus(
+            inputs = tokenizer(
                 text_a,
                 text_b,
                 add_special_tokens=True,
                 max_length=max_length,
-                pad_to_max_length=True,
+                padding="max_length",
+                truncation=True,
                 return_overflowing_tokens=True,
             )
             if "num_truncated_tokens" in inputs and inputs["num_truncated_tokens"] > 0: