feat: add TypeScript definitions for CombinedFieldsQuery

[Seung-o]

Description

This PR adds missing TypeScript definitions for CombinedFieldsQuery in src/index.d.ts. The JavaScript implementation already exists and is exported properly, but TypeScript users were unable to use this query type due to missing type definitions.

Changes

• ✨ Added CombinedFieldsQuery class definition with all methods and proper typing
• ✨ Added combinedFieldsQuery factory function definition
• ✨ Added comprehensive JSDoc comments with examples
• ✅ Added TypeScript test cases in test/typedef.test.ts

Type Definitions Added

Class Definition

export class CombinedFieldsQuery extends FullTextQueryBase {
    constructor(fields?: string[] | string, queryString?: string);
    field(field: string): this;
    fields(fields: string[]): this;
    autoGenerateSynonymsPhraseQuery(enable: boolean): this;
    operator(operator: 'and' | 'or'): this;
    zeroTermsQuery(behavior: 'all' | 'none'): this;
}

Factory Function

export function combinedFieldsQuery(
    fields?: string[] | string,
    queryString?: string
): CombinedFieldsQuery;

Testing

• ✅ All existing tests pass
• ✅ TypeScript compilation succeeds without errors
• ✅ New TypeScript test cases added and passing
• ✅ 100% code coverage maintained

Usage Example

import * as esb from 'elastic-builder';

// Factory function
const query1 = esb.combinedFieldsQuery(['title', 'body'], 'Quick brown fox')
    .operator('and')
    .autoGenerateSynonymsPhraseQuery(true);

// Class constructor
const query2 = new esb.CombinedFieldsQuery(['title', 'content'], 'search terms')
    .zeroTermsQuery('all');

Fixes

Resolves TypeScript compilation errors when using CombinedFieldsQuery in TypeScript projects.

---

Note: This query was added in Elasticsearch 7.13+ and the JavaScript implementation has been available, but TypeScript definitions were missing.

[github-actions]

🎉 This PR is included in version 3.4.0 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot 📦🚀

[sudo-suhas]

Thanks for the PR @Seung-o 🎉