Documentation Issues Related to Client Credentials Grant

Description:
Issue 1:
In [1], under Step 2 - Enable the Client Credentials grant type -> 5. Select Client Credentials., the attached image should be updated.

Issue 2:
In [2], under Step 5 - Obtain the access token -> Response, the response should be updated.

• POST and Host should be updated

> POST /oauth2/token HTTP/1.1
> Host: localhost:9443

• access_token should be in JWT format
• scope will not contain am_application_scope. Have to remove that.
• better to set the value of expires_in field to 3600 which is the default value.

Issue 3:
The section Set a custom validity time for the access token [3] should be removed since it is not supported from API-M 3.2.0 onwards

Note: Some of the changes have been done in 3.2.0 documentation [4] and have been nicely formatted.

[1] https://apim.docs.wso2.com/en/4.1.0/design/api-security/oauth2/grant-types/client-credentials-grant/#step-2-enable-the-client-credentials-grant-type
[2] https://apim.docs.wso2.com/en/4.1.0/design/api-security/oauth2/grant-types/client-credentials-grant/#step-5-obtain-the-access-token
[3] https://apim.docs.wso2.com/en/4.1.0/design/api-security/oauth2/grant-types/client-credentials-grant/#set-a-custom-validity-time-for-the-access-token
[4] https://apim.docs.wso2.com/en/3.2.0/learn/api-security/oauth2/grant-types/client-credentials-grant/#!

Start with the 4.1.0 client-credentials grant documentation sections linked in the issue and compare them with the corresponding 3.2.0 documentation. Update the Step 2 image and Step 5 response details, then remove the unsupported custom-validity section. Done means the 4.1.0 page matches the stated current behavior and formatting.