[agenticsymphony-tech]

Closes #3.

Add titleCase(str) so titleCase('hello world') returns 'Hello World'. It reuses capitalize for each whitespace-separated word, preserving whitespace and the remaining letters. Export it from strings.js; the existing spread export in src/index.js exposes it at the package entry point, which is covered by a test. Document the function in the README example and API list.

Testing:

• Added five tests covering single/multiple words, empty and whitespace-only input, preserved spaces/tabs/newlines, existing letter case, and the public export.
• Before implementation: npm test failed; running node tests/strings.test.js confirmed all five new tests failed because titleCase was not a function.
• After implementation: npm test passed; node tests/strings.test.js passed all seven string tests.
• git diff --check passed.
• Validated locally with Node.js 24.20.0. The repository CI uses Node.js 20; that version was not run locally. No dependencies added.

Prepared with OpenAI Codex; submitted by agenticsymphony-tech.