docs: add migration guide for vis rec 4.0.0

Author: mamoonraja

MIGRATION-v4.md

@@ -0,0 +1,230 @@
+### Unity SDK V4 Migration guide
+
+#### Authentication
+
+##### v3.x.x
+
+Previously different `Config` objects were used for authentication.
+
+```cs
+void Example()
+{
+    TokenOptions iamTokenOptions = new TokenOptions(
+        Apikey: "{iam-apikey}"
+    );
+    service = new AssistantService("{versionDate}", iamTokenOptions);
+    service.SetEndpoint("{service-endpoint}");
+}
+```
+
+Or constructors accepted `TokenOptions` or `username` and `password`.
+
+```cs
+void Example()
+{
+    service = new AssistantService("{tokenOptions}", "{versionDate}");
+    service2 = new DiscoveryService("{username}", "{password}", "{versionDate}");
+}
+```
+
+##### v4.x.x
+
+Now we use an `Authenticator` to authenticate the service. Available authentication schemes include `IamAuthenticator`, `BasicAuthenticator`, `CloudPakForDataAuthenticator` and `BearerTokenAuthenticator`
+
+###### IamAuthenticator
+
+```cs
+void Example()
+{
+    IamAuthenticator authenticator = new IamAuthenticator(
+        apikey: "{apikey}"
+    );
+    var service = new AssistantService("{versionDate}", authenticator);
+    service.SetServiceUrl("{serviceUrl}");
+}
+```
+
+##### BasicAuthenticator
+
+```cs
+void Example()
+{
+    BasicAuthenticator authenticator = new BasicAuthenticator(
+        username: "{username}",
+        password: "{password}"
+    );
+    var service = new AssistantService("{versionDate}", authenticator);
+    service.SetServiceUrl("{serviceUrl}");
+}
+```
+
+###### BearerTokenAuthenticator
+
+```cs
+void Example()
+{
+    BearerTokenAuthenticator authenticator = new BearerTokenAuthenticator(
+        bearerToken: "{bearerToken}"
+    );
+    var service = new AssistantService("{versionDate}", authenticator);
+    service.SetServiceUrl("{serviceUrl}");
+}
+```
+
+###### CloudPakForDataAuthenticator
+
+```cs
+void Example()
+{
+    CloudPakForDataAuthenticator authenticator = new CloudPakForDataAuthenticator(
+        url: "https://{cp4d_cluster_host}{:port}",
+        username: "{username}",
+        password: "{password}"
+    );
+    var service = new AssistantService("{version-date}", authenticator);
+    service.SetServiceUrl("{serviceUrl}");
+    var results = service.Message("{workspace-id}", "{message-request}");
+}
+```
+
+Constructors that did not take an `Authenticator` were removed.
+
+#### Supplying credentials
+
+You can supply credentials to your service using external `ibm-credentials.env` files.
+
+```cs
+AssistantService service = new AssistantService("{version-date}");
+var listWorkspacesResult = service.ListWorkspaces();
+```
+
+##### v3.x.x
+
+Previously we would look for these files first in the system `home` directory, followed by the current project directory.
+
+##### v4.x.x
+Now in order to allow developers to have different configurations for each project we look first in the current project directory, followed by the home directory.
+
+#### Setting the service url
+
+##### v3.x.x
+
+Previously we set the service url via SetEndpoint() method.
+
+```cs
+void Example()
+{
+    TokenOptions iamTokenOptions = new TokenOptions(
+        apikey: "{iam-apikey}"
+    );
+    service = new AssistantService("{versionDate}", iamTokenOptions);
+    service.SetEndpoint("{service-endpoint}");
+}
+```
+
+##### v4.x.x
+
+Now we set the service url via the SetServiceUrl() method.
+
+```cs
+void Example()
+{
+    IamAuthenticator authenticator = new IamAuthenticator(
+        apikey: "{apikey}"
+    );
+    var service = new AssistantService("{versionDate}", authenticator);
+    service.SetServiceUrl("{serviceUrl}");
+}
+```
+
+#### Service changes
+
+##### Assistant v1
+
+* `includeCount` is no longer a parameter of the `ListWorkspaces()` method
+* `includeCount` is no longer a parameter of the `ListIntents()` method
+* `includeCount` is no longer a parameter of the `ListExamples()` method
+* `includeCount` is no longer a parameter of the `ListCounterexamples()` method
+* `includeCount` is no longer a parameter of the `ListEntities()` method
+* `includeCount` is no longer a parameter of the `ListValues()` method
+* `includeCount` is no longer a parameter of the `ListSynonyms()` method
+* `includeCount` is no longer a parameter of the `ListDialogNodes()` method
+* `valueType` was renamed to `type` in the `CreateValue()` method
+* `newValueType` was renamed to `newType` in the `UpdateValue()` method
+* `nodeType` was renamed to `type` in the `CreateDialogNode()` method
+* `nodeType` was renamed to `type` in the `CreateDialogNode()` method
+* `newNodeType` was renamed to `newType` in the `UpdateDialogNode()` method
+* `ValueTypeEnumValue` was renamed to `TypeEnumValue` in the `CreateValue` model
+* `ValueType` was renamed to `Type` in the `CreateValue` model
+* `NodeTypeEnumValue` was renamed to `TypeEnumValue` in the `DialogNode` model
+* `NodeType` was renamed to `Type` in the `DialogNode` model
+* `ActionTypeEnumValue` was renamed to `TypeEnumValue` in the `DialogNodeAction` model
+* `ActionType` was renamed to `Type` in the `DialogNodeAction` model
+* `SEARCH_SKILL` constant was added to the `DialogNodeOutputGeneric` model
+* `QueryTypeEnumValue` constants were added to the `DialogNodeOutputGeneric` model
+* `QueryType` property was added to the `DialogNodeOutputGeneric` model
+* `Query` property was added to the `DialogNodeOutputGeneric` model
+* `Filter` property was added to the `DialogNodeOutputGeneric` model
+* `DiscoveryVersion` property was added to the `DialogNodeOutputGeneric` model
+* `Output` property type was converted from `Dictionary<string, object>` to `DialogSuggestionOutput` in the `DialogSuggestion` model
+* `LogMessage` model no longer has `additionalProperties`
+* `DialogRuntimeResponseGeneric` was renamed to `RuntimeResponseGeneric`
+* `RuntimeEntity` model no longer has `additionalProperties`
+* `RuntimeIntent` model no longer has `additionalProperties`
+* `ValueTypeEnumValue` was renamed to `TypeEnumValue` in the `Value` model
+* `ValueType` was renamed to `Type` in the `Value` model
+
+##### Assistant v2
+
+* `ActionTypeEnumValue` was renamed to `TypeEnumValue` in the `DialogNodeAction` model
+* `ActionType` was renamed to `Type` in the `DialogNodeAction` model
+* `DialogRuntimeResponseGeneric` was renamed to `RuntimeResponseGeneric`
+
+##### Compare Comply v1
+
+* `ConvertToHtml()` method does not require a `filename` parameter
+
+##### Discovery v1
+
+* `returnFields` was renamed to `_return` in the `Query()` method
+* `loggingOptOut` was renamed to `xWatsonLoggingOptOut` in the `Query()` method
+* `spellingSuggestions` was added to the `Query()` method
+* `collectionIds` is no longer a parameter of the `Query()` method
+* `returnFields` was renamed to `_return` in the `QueryNotices()` method
+* `loggingOptOut` was renamed to `xWatsonLoggingOptOut` in the `FederatedQuery()` method
+* `collectionIds` is now required in the `FederatedQuery()` method
+* `collectionIds` changed position in the `FederatedQuery()` method
+* `returnFields` was renamed to `_return` in the `FederatedQuery()` method
+* `returnFields` was renamed to `_return` in the `FederatedQueryNotices()` method
+* `EnrichmentName` was renamed to `_Enrichment` in the `Enrichment` model
+* `FieldTypeEnumValue` was renamed to `TypeEnumValue` in the `Field` model
+* `FieldType` was renamed to `Type` in the `Field` model
+* `FieldName` was renamed to `_Field` in the `Field` model
+* `TestConfigurationInEnvironment()` method was removed
+* `QueryEntities()` method was removed
+* `QueryRelations()` method was removed
+
+##### Language Translator v3
+
+* `defaultModels` was renamed to `_default` in the `ListModels()` method
+* `TranslationOutput` was renamed to `_Translation` in the `Translation` model
+
+##### Natural Language Classifier v1
+
+* `metadata` was renamed to `trainingMetadata` in the `CreateClassifier()` method
+
+##### Speech to Text v1
+
+* `strict` is no longer a parameter of the `TrainAcousticModel()` method
+* `FinalResults` was renamed to `Final` in the `SpeakerLabelsResult` model
+* `FinalResults` was renamed to `Final` in the `SpeechRecognitionResult` model
+
+##### Visual Recognition v3
+
+* `DetectFaces()` method was removed
+* `ClassName` was renamed to `_Class` in the `ClassResult` model
+* `ClassName` was renamed to `_Class` in the `ModelClass` model
+
+##### Visual Recognition v4
+
+* New service!