From 817201553d790c8b53a3aef17ed87721a9d35595 Mon Sep 17 00:00:00 2001
From: Xinyu Mavis Liu <x389liu@gmail.com>
Date: Sun, 1 Nov 2020 12:59:41 -0500
Subject: [PATCH] Update README for indexing additional fields (#239)

---
 README.md | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/README.md b/README.md
index bfc8cc35f..e04d8735b 100644
--- a/README.md
+++ b/README.md
@@ -220,6 +220,21 @@ for i in range(len(hits)):
     print(f'{i+1:2} {hits[i].docid:15} {hits[i].score:.5f}')
 ```
 
+You can also add extra fields in your documents when needed, e.g. text features.
+For example, the [SpaCy](https://spacy.io/usage/linguistic-features#named-entities) Named Entity Recognition (NER) result of `contents` could be stored as an additional field `NER`.
+
+```json
+{
+  "id": "doc1",
+  "contents": "Apple is looking at buying U.K. startup for $1 billion.",
+  "NER": {
+            "ORG": ["Apple"],
+            "GPE": ["U.K."],
+            "MONEY": ["$1 billion"]
+         }
+}
+```
+
 Happy honking!
 
 ## Additional Documentation