docs: good working example

Author: TANGUY Antoine

README.md

@@ -31,15 +31,15 @@ Once you have [installed](#installation) the node module in your project, you ca
 ```javascript
 const SibApiV3Sdk = require('@sendinblue/client')
 
-let apiInstance = new SibApiV3Sdk.AccountApi()
+const apiInstance = new SibApiV3Sdk.AccountApi()
 
 // Configure API key authorization: apiKey
 
 apiInstance.setApiKey(SibApiV3Sdk.AccountApiApiKeys.apiKey, 'YOUR API KEY')
 
 apiInstance.getAccount().then(
   function (data) {
-    console.log('API called successfully. Returned data: ' + data)
+    console.log('API called successfully. Returned data: ', data.body)
   },
   function (error) {
     console.error(error)
@@ -50,21 +50,21 @@ apiInstance.getAccount().then(
 ```javascript
 const SibApiV3Sdk = require('@sendinblue/client')
 
-let apiInstance = new SibApiV3Sdk.ContactsApi()
+const apiInstance = new SibApiV3Sdk.ContactsApi()
 
 // Configure API key authorization: apiKey
 
 apiInstance.setApiKey(SibApiV3Sdk.AccountApiApiKeys.apiKey, 'YOUR API KEY')
 
-let limit = 10 // Number | Number of documents per page
-let offset = 0 // Number | Index of the first document of the page
+const limit = 10 // Number | Number of documents per page
+const offset = 0 // Number | Index of the first document of the page
 
 apiInstance.getLists(limit, offset).then(
   function (data) {
-    console.log('API called successfully. Returned data: ' + data)
+    console.log('API called successfully. Returned data: ', data.body)
     apiInstance.getAttributes().then(
       function (data) {
-        console.log('API called successfully. Returned data: ' + data)
+        console.log('API called successfully. Returned data: ', data.body)
       },
       function (error) {
         console.error(error)