Documentation Support for Lightweight API Key Generation and Remove API Key Subscription Validation Enabling Configuration Support from Docs

[dakshina99]

Description:

This issue tracks the need for comprehensive documentation regarding the following two areas in WSO2 API Manager:

1. Lightweight API Key:

WSO2 API Manager introduces a Lightweight API Key having limited set of claims. A detailed documentation on the usage and configuration of the Lightweight API Key feature need to be added.

2. Remove API Key Subscription Validation Enabling Configuration:

API Key subscription validation is a mandatory check, and the related configuration has been removed. Documentation needs to be updated to reflect this change.