CONTRIBUTING.md lost its opening lines; every code fence after line 20 pairs wrongly #113

CONTRIBUTING.md on main has lost its opening lines. It begins, straight after the SPDX comment, with # Clone the repository followed by bare shell commands, so the title, the introduction and the opening ```bash fence are missing.

Because the opening fence is gone, the fence on line 20 is treated as an opening fence, and every later code block pairs with the wrong partner:

• the repository-structure tree renders as prose;
• lines 50–103 (How to Contribute … Development Workflow) render as a single code block;
• the Conventional Commits example renders as prose.

Found while reviewing #112. CodeRabbit flagged a fence problem there, which is how this came to light.

Acceptance criteria

• Restore the missing header and the opening fence, taking them from the RSR CONTRIBUTING template this file was generated from.
• POST /markdown (mode gfm) output for the file shows every heading as a heading, and shows only the intended examples inside <pre>.

🤖 Generated with Claude Code

https://claude.ai/code/session_01WRvDivYwLSeVCJUrfjic3f