docs: update readme and secrets baseline

Author: apaparazzi0329

.secrets.baseline

@@ -3,7 +3,7 @@
     "files": "package-lock.json|credentials.json|^.secrets.baseline$",
     "lines": null
   },
-  "generated_at": "2023-03-09T15:38:18Z",
+  "generated_at": "2024-02-26T19:16:17Z",
   "plugins_used": [
     {
       "name": "AWSKeyDetector"
@@ -70,7 +70,7 @@
         "hashed_secret": "939999726d2023fca902233e45790c08081dc91b",
         "is_secret": false,
         "is_verified": false,
-        "line_number": 150,
+        "line_number": 182,
         "type": "Hex High Entropy String",
         "verified_result": null
       }

README.md

@@ -238,6 +238,19 @@ service.setServiceUrl("<service CP4D URL>");
 
 Be sure to both disable SSL verification when authenticating and set the endpoint explicitly to the URL given in Cloud Pak for Data.
 
+#### MCSP
+To use the SDK through a third party cloud provider (such as AWS), use the `MCSPAuthenticator`. This will require the base endpoint URL for the MCSP token service (e.g. https://iam.platform.saas.ibm.com) and an apikey. 
+
+```java
+// letting the SDK manage the token
+Authenticator authenticator = new MCSPAuthenticator.Builder()
+            .apikey("apikey")
+            .url("token_service_endpoint")
+            .build();
+Assistant service = new Assistant("2023-06-15", authenticator);
+service.setServiceUrl("<url_as_per_region>");
+```
+
 ## Using the SDK
 
 ### Parsing responses