Add LayoutLMForQuestionAnswering model (#18407)

* Add LayoutLMForQuestionAnswering model

* Fix output

* Remove TF TODOs

* Add test cases

* Add docs

* TF implementation

* Fix PT/TF equivalence

* Fix loss

* make fixup

* Fix up documentation code examples

* Fix up documentation examples + test them

* Remove LayoutLMForQuestionAnswering from the auto mapping

* Docstrings

* Add better docstrings

* Undo whitespace changes

* Update tokenizers in comments

* Fixup code and remove `from_pt=True`

* Fix tests

* Revert some unexpected docstring changes

* Fix tests by overriding _prepare_for_class

Co-authored-by: Ankur Goyal <ankur@impira.com>

utils/check_repo.py

@@ -161,6 +161,7 @@ IGNORE_NON_AUTO_CONFIGURED = PRIVATE_MODELS.copy() + [
     "FlavaImageModel",
     "FlavaMultimodalModel",
     "GPT2DoubleHeadsModel",
+    "LayoutLMForQuestionAnswering",
     "LukeForMaskedLM",
     "LukeForEntityClassification",
     "LukeForEntityPairClassification",
@@ -178,6 +179,7 @@ IGNORE_NON_AUTO_CONFIGURED = PRIVATE_MODELS.copy() + [
     "RealmReader",
     "TFDPRReader",
     "TFGPT2DoubleHeadsModel",
+    "TFLayoutLMForQuestionAnswering",
     "TFOpenAIGPTDoubleHeadsModel",
     "TFRagModel",
     "TFRagSequenceForGeneration",

utils/documentation_tests.txt

@@ -38,6 +38,8 @@ src/transformers/models/glpn/modeling_glpn.py
 src/transformers/models/gpt2/modeling_gpt2.py
 src/transformers/models/gptj/modeling_gptj.py
 src/transformers/models/hubert/modeling_hubert.py
+src/transformers/models/layoutlm/modeling_layoutlm.py
+src/transformers/models/layoutlm/modeling_tf_layoutlm.py
 src/transformers/models/layoutlmv2/modeling_layoutlmv2.py
 src/transformers/models/layoutlmv3/modeling_layoutlmv3.py
 src/transformers/models/layoutlmv3/modeling_tf_layoutlmv3.py