add wide.md from tensorflow/tensorflow
add wide.md from tensorflow/tensorflow

from https://github.com/tensorflow/tensorflow/blob/8a6ef2cb4f98bacc1f821f60c21914b4bd5faaef/tensorflow/docs_src/tutorials/representation/wide.md

cshallue/models,tombstone/models,tombstone/models,alexgorban/models,tombstone/models,derekjchow/models,alexgorban/models,tombstone/models,alexgorban/models,alexgorban/models,derekjchow/models,derekjchow/models,derekjchow/models,alexgorban/models,cshallue/models,tombstone/models,tombstone/models,derekjchow/models,cshallue/models,cshallue/models,cshallue/models