Update docs/resources/guild.mdx

Co-authored-by: Droid <[email protected]>

Author: appellation

docs/resources/guild.mdx

@@ -1019,7 +1019,7 @@ This endpoint supports the `X-Audit-Log-Reason` header.
 |---------|---------|--------------------------------------|-----------------|
 | nick?   | ?string | value to set user's nickname to      | CHANGE_NICKNAME |
 | banner? | ?string | data URI base64 encoded banner image |                 |
-| avatar? | ?string | data URL base64 encoded avatar image |                 |
+| avatar? | ?string | data URI base64 encoded avatar image |                 |
 | bio?    | ?string | guild member bio                     |                 |
 
 ## Modify Current User Nick