docs: Add PR title format documentation to copilot-instructions

[Copilot]

Documents Conventional Commits PR title requirements in .github/copilot-instructions.md to align with existing CI enforcement in .github/workflows/chore.yml.

Changes

• Added "Pull request titles (required)" subsection under "When Making Changes"
• Documented format: <type>[!]: <Subject>
• Listed all 11 allowed commit types (feat, fix, docs, style, refactor, perf, test, build, ci, chore, revert)
• Specified rules for breaking changes (!) and subject formatting (uppercase start, no trailing . or space)
• No scopes mentioned (not enforced by CI)

Positioned after the existing 5-item checklist to maintain logical flow from code changes to PR conventions.

Original prompt

Create a PR in Quantco/dataframely (base branch main) that updates the existing file .github/copilot-instructions.md.

Change requested

Add a new section under "## When Making Changes", placed after the existing numbered checklist items (after item 5: "API changes").

Insert the following subsection exactly (no mentions of scopes):

• Heading: ### Pull request titles (required)
• Text describing Conventional Commits PR title format: <type>[!]: <Subject>
• List of allowed type values with descriptions:
  • feat: A new feature
  • fix: A bug fix
  • docs: Documentation only changes
  • style: Changes that do not affect the meaning of the code (white-space, formatting, missing semi-colons, etc)
  • refactor: A code change that neither fixes a bug nor adds a feature
  • perf: A code change that improves performance
  • test: Adding missing tests or correcting existing tests
  • build: Changes that affect the build system or external dependencies
  • ci: Changes to our CI configuration files and scripts
  • chore: Other changes that don't modify src or test files
  • revert: Reverts a previous commit
• Additional rules:
  • use ! only for breaking changes
  • Subject must start with an uppercase letter and must not end with . or a trailing space

Acceptance criteria

• The new subsection appears after the existing numbered list in ## When Making Changes.
• No mention of scopes appears anywhere in the added text.
• PR passes existing CI checks.

Reference

The repository already enforces the PR title subject pattern in .github/workflows/chore.yml via subjectPattern: ^[A-Z].+[^. ]$.

This pull request was created from Copilot chat.

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💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.00%. Comparing base (b813ac9) to head (64d0c70).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff            @@
##              main      #249   +/-   ##
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  Coverage   100.00%   100.00%           
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  Files           53        53           
  Lines         3066      3066           
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  Hits          3066      3066           

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