typo fix

Author: aahill

articles/cognitive-services/text-analytics/how-tos/text-analytics-how-to-entity-linking.md

@@ -115,7 +115,7 @@ Named Entity Recognition v2 uses a single endpoint for NER and entity linking re
 
 You must have JSON documents in this format: ID, text, language.
 
-Each document must must be under 5,120 characters, and you can have up to 1,000 items (IDs) per collection. The collection is submitted in the body of the request.
+Each document must be under 5,120 characters, and you can have up to 1,000 items (IDs) per collection. The collection is submitted in the body of the request.
 
 ### Structure the request