Improve repository with better documentation and templates

Add new issue templates, pull request template, contributing guidelines, and code of conduct, and update release notes. * **Issue Templates** - Add `documentation_improvement.md` for suggesting documentation improvements. - Add `question.md` for asking questions about the project. * **Pull Request Template** - Add `PULL_REQUEST_TEMPLATE.md` to guide contributors in describing their changes, related issues, and additional context. * **Contributing Guidelines** - Add `CONTRIBUTING.md` to provide guidelines for reporting issues, submitting pull requests, and following coding standards. * **Code of Conduct** - Add `CODE_OF_CONDUCT.md` to establish expected behavior, unacceptable behavior, and enforcement responsibilities. * **Release Notes** - Update release notes for versions 7.22.1 to 7.32 to include more detailed descriptions, links to relevant documentation, and organize notes by categories such as "New Features," "Improvements," and "Bug Fixes." --- For more details, open the [Copilot Workspace session](https://copilot-workspace.githubnext.com/postmanlabs/postman-app-support/tree/release-app-7.32?shareId=XXXX-XXXX-XXXX-XXXX).