chore: Update guide (#2046)

Author: deekshas8

docs-js/guides/upgrade-to-version-4.mdx

@@ -9,14 +9,13 @@ description: This document will guide you through the upgrade process from versi
 
 # How to Upgrade to Version 4 of the SAP Cloud SDK for JavaScript <!-- omit from toc -->
 
-This document will guide you through the steps necessary to upgrade to version 4 of the SAP Cloud SDK.
-Depending on your project, some steps might not be applicable.
-The To-Do list is:
+This document outlines changes introduced in version 4 of the SAP Cloud SDK and provides guidance for updating your project where needed.
+Some points highlight changes in default behavior rather than required actions.
 
 - [Update Your Project Dependencies](#update-your-project-dependencies)
 - [Update to Node 22 or Newer](#update-to-node-22-or-newer)
-- [Set `useCache` explicitly to `false` to turn off destination caching](#set-usecache-explicitly-to-false-to-turn-off-destination-caching)
-- [Set `iasToXsuaaTokenExchange` to `true` to enable IAS to XSUAA token exchange](#set-iastoxsuaatokenexchange-to-true-to-enable-ias-to-xsuaa-token-exchange)
+- [Destination caching is enabled by default](#destination-caching-is-enabled-by-default)
+- [`iasToXsuaaTokenExchange` option is `false` by default](#iastoxsuaatokenexchange-option-is-false-by-default)
 - [Remove Deprecated Content](#remove-deprecated-content)
 
 ## Update Your Project Dependencies
@@ -34,7 +33,7 @@ All SAP Cloud SDK for JavaScript libraries now support node 22 (LTS) as the **mi
 If you are using a node version older than 22, update your runtime environment to a newer version.
 On Cloud Foundry you can do this by [setting the node engine in your `package.json`](https://docs.cloudfoundry.org/buildpacks/node/index.html#runtime).
 
-## Set `useCache` explicitly to `false` to turn off destination caching
+## Destination caching is enabled by default
 
 **Destination caching while retrieving destinations via the destination service is now enabled by default.**
 
@@ -46,7 +45,7 @@ To disable caching set `useCache: false` in the options, for example in `execute
 .execute({ destinationName: 'DESTINATION', jwt: 'JWT', useCache: false })
 ```
 
-## Set `iasToXsuaaTokenExchange` to `true` to enable IAS to XSUAA token exchange
+## `iasToXsuaaTokenExchange` option is `false` by default
 
 **Token exchange from IAS to XSUAA is now disabled by default.
 Set `iasToXsuaaTokenExchange` to `true` explicitly if token exchange is expected.**