Adding a docnn config for dense features as an example (facebookresea…

…rch#415)

Summary:
This will help show users how to use dense features. It will also enable us to quickly experiment with supporting and adding dense features to newer models.

trained, tested a model with this feature.
Pull Request resolved: facebookresearch#415

Reviewed By: hikushalhere

Differential Revision: D14533972

Pulled By: snisarg

fbshipit-source-id: e89aa2c1c9e7c2391d3e18532524e4114ddf8a0a

demo/configs/docnn_dense_feat.json

@@ -0,0 +1,17 @@
+{
+  "task": {
+    "DocClassificationTask": {
+      "features" : {
+        "dense_feat" : {
+          "dim": 10
+        }
+      },
+      "data_handler": {
+        "columns_to_read": ["doc_label", "text", "dict_feat", "dense_feat"],
+        "train_path": "tests/data/train_dense_features_tiny.tsv",
+        "eval_path": "tests/data/test_dense_features_tiny.tsv",
+        "test_path": "tests/data/test_dense_features_tiny.tsv"
+      }
+    }
+  }
+}