fix: use correct type for cookie jar option

Also, document the cookie jar support correctly.

README.md

@@ -80,7 +80,7 @@ The debug logger can be configured to be used for more than one library. In exam
 ``DEBUG=ibm-cloud-sdk-core:debug,other-lib:debug``
 
 ## Cookie Jar Support
-By default, cookies are not supported in the SDK requests.  If your SDK would benefit from this functionality, simply edit your code to instantiate a cookie jar (or instruct your users to do so) and pass it in the object containing configuration options to the `BaseService` class, as shown below.
+By default, cookies are not supported in the SDK requests.  If your SDK would benefit from this functionality, simply edit your code to instantiate a cookie jar (or instruct your users to do so) and pass it in the object containing configuration options to the `BaseService` class, as shown below. If the Boolean value `true` is given for the `jar` field, the SDK core will create a default instance of a [Tough Cookie](https://www.npmjs.com/package/tough-cookie).
 
 ```ts
 import tough = require('tough-cookie');
@@ -95,8 +95,6 @@ class MyClass extends BaseService {
 }
 ```
 
-The example above uses [Tough Cookie](https://www.npmjs.com/package/tough-cookie) to provide these capabilities, but other cookie jar libraries can be used.
-
 ## Issues
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