Add a CONTRIBUTING guide, PR/issue templates, and a CODEOWNERS file

[mikewheeleer]

Document the contribution workflow with templates and CODEOWNERS

Description

The only contributor guidance lives in a short "Contributing" section of README.md, and .github/ contains only workflows/ci.yml. There are no issue/PR templates, no CONTRIBUTING.md, and no CODEOWNERS, which slows down the campaign's incoming contributions. This issue adds the standard GitHub contribution scaffolding.

Requirements and context

• Repository scope: Agentpay-Org/Agentpay-backend only.
• Add CONTRIBUTING.md covering setup, the branch-naming convention used across these issues, the commit-message style, and the test/lint/coverage bar.
• Add .github/PULL_REQUEST_TEMPLATE.md with a checklist (tests added, docs updated, npm test/npm run lint green, security notes).
• Add .github/ISSUE_TEMPLATE/ forms for bug reports and feature requests.
• Add a .github/CODEOWNERS mapping the repo to the maintainers.

Suggested execution

• Fork the repo and create a branch
• git checkout -b docs/docs-25-contributing-templates
• Implement changes
  • Write code in: no production change; add files under .github/ and CONTRIBUTING.md.
  • Write comprehensive tests in: none required.
  • Add documentation: link CONTRIBUTING.md from README.md.
  • Keep templates concise and aligned with the existing CI (npm ci, build, test).
  • Validate security assumptions: templates remind contributors not to commit secrets.
• Test and commit

Test and commit

• Run npm run build and npm test to confirm nothing breaks.
• Verify the templates render on a draft PR/issue.
• Include a note in the PR listing the files added.

Example commit message

docs: add contributing guide, pr/issue templates, and codeowners

Guidelines

• Minimum 95 percent test coverage for impacted modules (where applicable).
• Clear, reviewer-focused documentation.
• Timeframe: 96 hours.

Community & contribution rewards

• 💬 Join the AgentPay community on Discord for questions, reviews, and faster merges: https://discord.gg/eXvRKkgcv
• ⭐ This is a GrantFox OSS / Official Campaign task and may be rewarded. When your PR is merged you'll be prompted to rate the project — if this issue and the maintainers helped you ship, we'd be grateful for a 5-star rating. Clear questions in Discord and tidy, well-tested PRs are the fastest path to a merge and a reward.