docs: document KeyEndorsementPolicy class for State-Based Endorsement (#307)

[JhaSourav07]

Description

This PR Closes ** #307** by adding documentation for the KeyEndorsementPolicy class to the official Node.js reference documentation.
The KeyEndorsementPolicy class is essential for implementing State-Based Endorsement (SBE) but was previously missing from the generated API docs.

This update ensures the class and its methods are properly documented and visible in the generated documentation, improving discoverability and developer usability.

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Changes

Documentation Configuration

• Updated docs/_jsdoc.json to include libraries/fabric-shim/lib/utils/statebased.js in the source scanning path so the class is included during documentation generation.

JSDoc Enhancements

• Added comprehensive JSDoc comments for the KeyEndorsementPolicy class and its methods:

  • addOrgs
  • delOrgs
  • listOrgs
  • getPolicy

TypeScript Definitions

• Added the KeyEndorsementPolicy class to libraries/fabric-shim/types/index.d.ts.

Library Export

• Verified that KeyEndorsementPolicy is correctly exported in libraries/fabric-shim/index.js so it can be used by consumers.

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Verification

• Documentation: Successfully generated local docs using npm run build inside the docs folder. The KeyEndorsementPolicy class now appears in the sidebar with full method documentation.
• Linting: Ran npm run lint inside libraries/fabric-shim with 0 errors.
• Build: Successfully executed rush rebuild for the entire monorepo.

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Checklist

• I have added the Signed-off-by line to my commit message (DCO).
• My changes follow the project's coding style and linting rules.
• I have verified that the documentation generates correctly.
• I have updated the TypeScript definitions to match the new documentation.

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Screenshots

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Closes #307