Add comprehensive GitHub issue templates for Redpanda Connect

[Copilot]

This PR adds a complete set of GitHub issue templates to improve issue triage and provide better guidance to contributors and users reporting issues.

What's Added

Created 6 specialized issue templates plus configuration:

🐛 Bug Report Template

• Structured form with required fields for bug description, reproduction steps, and environment details
• YAML configuration section for easy sharing (with syntax highlighting)
• Dropdowns for OS, architecture, and deployment method
• Validation to ensure critical information is provided

🚀 Feature Request Template

• Clear sections for problem statement, proposed solution, and use cases
• Configuration examples to help clarify the expected API
• Feature type categorization (input/output connector, processor, core functionality, etc.)
• Alternatives consideration section

🔌 Connector Certification Request Template

• Project-specific template based on the certification guidelines in CONTRIBUTING.md
• Business justification and market relevance sections
• Technical requirements checklist aligned with the certification criteria (sections 1.1-1.3)
• Implementation timeline and resource planning
• References the official connector certification guidelines

⚡ Performance Issue Template

• Specialized for stream processor performance problems
• Resource usage monitoring sections (CPU, memory, throughput, latency)
• Workload characteristics (message size, rate, data patterns)
• Performance profiling checklist (CPU profiles, memory profiles, benchmarks)
• Timeline and reproduction information

📚 Documentation Improvement Template

• Categorized improvement types (missing info, unclear content, broken links, etc.)
• Before/after sections for proposed changes
• Target audience selection (new users, advanced users, etc.)
• Priority levels and contribution willingness options

❓ Question/Support Request Template

• Structured support form with research verification
• Urgency levels for proper prioritization
• Guidance toward GitHub Discussions and Slack for complex questions

Configuration File

• Disables blank issues to ensure proper categorization
• Provides helpful contact links:
  • Security vulnerability reporting ([email protected])
  • Official documentation
  • GitHub Discussions
  • Redpanda Community Slack

Key Features

• Project-tailored: Templates reference Redpanda Connect's specific components (inputs, processors, outputs) and certification guidelines
• Comprehensive validation: Required fields ensure sufficient information for efficient triage
• YAML syntax highlighting: Configuration sections use proper syntax highlighting for better readability
• Professional UX: Modern GitHub issue form format with dropdowns, checkboxes, and structured inputs
• Community guidance: Clear direction to appropriate channels (Discussions, Slack) for different types of requests

Benefits

1. Improved issue quality: Structured forms ensure reporters provide necessary information
2. Faster triage: Consistent formatting and required fields help maintainers quickly understand issues
3. Better user experience: Clear guidance and examples help users report issues effectively
4. Project-specific workflows: The connector certification template supports the project's certification process
5. Reduced back-and-forth: Comprehensive templates minimize the need for follow-up questions

All templates follow GitHub's issue form syntax and have been validated for proper YAML structure.

---

✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}