Add model like (#14992)

* Add new model like command

* Bad doc-styler

* black and doc-styler, stop fighting!

* black and doc-styler, stop fighting!

* At last

* Clean up

* Typo

* Bad doc-styler

* Bad doc-styler

* All good maybe?

* Use constants

* Add doc and type hints

* More cleaning

* Add doc

* Fix Copied from

* Doc template

* Use typing.Pattern instead

* Framework-specific files

* Fixes

* Select frameworks clean model init

* Deal with frameworks in main init

* fixes

* Last fix

* Prompt user for info

* Delete exemple config

* Last fixes

* Add test config

* Fix bug with model_type included in each other

* Fixes

* More fixes

* More fixes

* Adapt config

* Remove print statements

* Will fix tokenization later, leave it broken for now

* Add test

* Quality

* Try this way

* Debug

* Maybe by setting the path?

* Let's try another way

* It should go better when actually passing the arg...

* Remove debug statements and style

* Fix config

* Add tests

* Test require the three backends

* intermediate commit

* Revamp pattern replacements and start work on feature extractors

* Adapt model info

* Finalize code for processors

* Fix in main init additions

* Finish questionnaire for processing classes

* Fix file name

* Fix for real

* Fix patterns

* Style

* Remove needless warnings

* Copied from should work now.

* Include Copied form in blocks

* Add test

* More fixes and tests

* Apply suggestions from code review

Co-authored-by: Lysandre Debut <lysandre@huggingface.co>

* Address review comment

Co-authored-by: Lysandre Debut <lysandre@huggingface.co>

tests/fixtures/add_distilbert_like_config.json

@@ -0,0 +1,19 @@
+{
+    "add_copied_from": true,
+    "old_model_type": "distilbert",
+    "new_model_patterns": {
+        "model_name": "BERT New",
+        "checkpoint": "huggingface/bert-new-base",
+        "model_type": "bert-new",
+        "model_lower_cased": "bert_new",
+        "model_camel_cased": "BertNew",
+        "model_upper_cased": "BERT_NEW",
+        "config_class": "BertNewConfig",
+        "tokenizer_class": "DistilBertTokenizer"
+    },
+    "frameworks": [
+        "pt",
+        "tf",
+        "flax"
+    ]
+}