docs: add connect factory props example

[landeqiming666]

Summary

• add a source-backed Redux connected counter example using MapStateToPropsFactory
• demonstrate per-instance memoization with ownProps while keeping inferred connected props type-safe
• include the example in README_SOURCE.md and regenerate README.md

Fixes #91

IssueHunt bounty: https://oss.issuehunt.io/r/piotrwitek/react-redux-typescript-guide/issues/91

Verification

• npm run ci-check
• cd playground && npm run lint
• cd playground && npm run tsc
• cd playground && CI=true npm test -- --watchAll=false
• git diff --check

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IssueHunt Summary

Referenced issues

This pull request has been submitted to:

• #91: Factory types for connect props

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[gemini-code-assist]

Code Review

This pull request introduces a new example of a Redux connected component using a factory for mapStateToProps to demonstrate per-instance memoization. The changes include documentation updates in README.md and README_SOURCE.md, the implementation of the factory-based connected component in fc-counter-connected-factory.tsx, and a corresponding usage example. A review comment identifies a missing label property in the OwnProps type definition, which is required for type compatibility with the underlying FCCounter component.

[gemini-code-assist]

The OwnProps type is missing the label property, which is required by the FCCounter component. Since label is passed to the connected component in the usage example but not provided by mapStateToProps or mapDispatchToProps, it must be included in OwnProps to ensure type safety and avoid a compilation error when calling connect.

Suggested change

	type OwnProps = {
	initialCount?: number;
	};
	type OwnProps = {
	label: string;
	initialCount?: number;
	};

[landeqiming666]

Follow-up pushed in 136a34d to address the Gemini review note: the connected factory example's OwnProps now includes the required label prop, and README.md was regenerated from the source example.\n\nValidation: npm run ci-check passed, including doctoc/readme generation and the pre-push clean-worktree check.