Fix the error in Api v3.1-preview.1 (Azure#10137)

* fix the error in api v3.1-preview.1

* update version

* fix newline

Author: HanLiMS

specification/cognitiveservices/data-plane/TextAnalytics/preview/v3.1-preview.1/TextAnalytics.json

@@ -1279,20 +1279,17 @@
       "type": "object",
       "required": [
         "id",
-        "detectedLanguages",
+        "detectedLanguage",
         "warnings"
       ],
       "properties": {
         "id": {
           "type": "string",
           "description": "Unique, non-empty document identifier."
         },
-        "detectedLanguages": {
-          "type": "array",
-          "description": "A list of extracted languages.",
-          "items": {
-            "$ref": "#/definitions/DetectedLanguage"
-          }
+        "detectedLanguage": {
+          "description": "Detected Language.",
+          "$ref": "#/definitions/DetectedLanguage"
         },
         "warnings": {
           "type": "array",

specification/cognitiveservices/data-plane/TextAnalytics/preview/v3.1-preview.1/examples/SuccessfulLanguagesRequest.json

@@ -27,35 +27,29 @@
         "documents": [
           {
             "id": "1",
-            "detectedLanguages": [
-              {
-                "name": "English",
-                "iso6391Name": "en",
-                "confidenceScore": 1
-              }
-            ],
+            "detectedLanguage": {
+              "name": "English",
+              "iso6391Name": "en",
+              "confidenceScore": 1
+            },
             "warnings": []
           },
           {
             "id": "2",
-            "detectedLanguages": [
-              {
-                "name": "French",
-                "iso6391Name": "fr",
-                "confidenceScore": 1
-              }
-            ],
+            "detectedLanguage": {
+              "name": "French",
+              "iso6391Name": "fr",
+              "confidenceScore": 1
+            },
             "warnings": []
           },
           {
             "id": "3",
-            "detectedLanguages": [
-              {
-                "name": "Spanish",
-                "iso6391Name": "es",
-                "confidenceScore": 1
-              }
-            ],
+            "detectedLanguage": {
+              "name": "Spanish",
+              "iso6391Name": "es",
+              "confidenceScore": 1
+            },
             "warnings": []
           }
         ],