[#2] Fill contributing.md file

[elfenpiff]

Notes for Reviewer

Pre-Review Checklist for the PR Author

1. Add sensible notes for the reviewer
2. PR title is short, expressive and meaningful
3. Relevant issues are linked
4. Every source code file has a copyright header with SPDX-License-Identifier: Apache-2.0 OR MIT
5. Branch follows the naming format (iox2-123-introduce-posix-ipc-example)
6. Commits messages are according to this guideline
   • Commit messages have the issue ID ([#123] Add posix ipc example)
   • Commit author matches Eclipse Contributor Agreement (and ECA is signed)
7. Tests follow the best practice for testing
8. Changelog updated in the unreleased section including API breaking changes
9. Assign PR to reviewer
10. All checks have passed (except task-list-completed)

Checklist for the PR Reviewer

• Commits are properly organized and messages are according to the guideline
• Unit tests have been written for new behavior
• Public API is documented
• PR title describes the changes

Post-review Checklist for the PR Author

1. All open points are addressed and tracked via issues

References

Use either 'Closes #123' or 'Relates to #123' to reference the corresponding issue.

Relates to #2

[codecov]

Codecov Report

Merging #50 (f05ce41) into main (b8485d3) will decrease coverage by 0.02%.
The diff coverage is n/a.

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #50      +/-   ##
==========================================
- Coverage   77.88%   77.86%   -0.02%     
==========================================
  Files         171      171              
  Lines       18638    18638              
==========================================
- Hits        14516    14513       -3     
- Misses       4122     4125       +3     

see 1 file with indirect coverage changes

[mossmaurice]

LGTM! Looking forward to many rusty 🦀 people joining.