Fix typo

Author: v-regandowner

articles/ai-services/openai/assistants-reference-threads.md

@@ -127,7 +127,7 @@ Modifies a thread.
 
 |Name | Type | Required | Description |
 |---  |---   |---       |--- |
-| metadata| map | Optional | Set of 16 key-value pairs that can be attached to an object. This can be useful for storing additional information about the object in a structured format. Keys can be a maximum of 64 characters long and values can be a maxium of 512 characters long.|
+| metadata| map | Optional | Set of 16 key-value pairs that can be attached to an object. This can be useful for storing additional information about the object in a structured format. Keys can be a maximum of 64 characters long and values can be a maximum of 512 characters long.|
 
 ### Returns