chore: improve issue template

[mikannkann]

Closes #96

[Copilot]

Pull Request Overview

This PR improves GitHub issue templates by simplifying required validations and adding a consistent "Details" section across all templates for additional context and supplementary information.

• Removes required validation from summary fields to make templates more flexible
• Removes specific sections like "Acceptance Criteria" to reduce template complexity
• Adds a standardized "Details" section to all four issue templates for supplementary information

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

File	Description
.github/ISSUE_TEMPLATE/01-enhancement.yml	Removes required validation and acceptance criteria section, adds Details field
.github/ISSUE_TEMPLATE/02-bug.yml	Removes required validation, improves reproduction format, adds Details field
.github/ISSUE_TEMPLATE/03-refactor.yml	Removes required validation and adds Details field
.github/ISSUE_TEMPLATE/04-epic.yml	Removes required validation and acceptance criteria section, adds Details field

---

_{Tip: Customize your code reviews with copilot-instructions.md. Create the file or learn how to get started.}