Add announcement document

[elfenpiff]

Notes for Reviewer

Pre-Review Checklist for the PR Author

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

[codecov[bot]]

Codecov Report

Merging #67 (346ba62) into main (323f40e) will decrease coverage by 0.03%. Report is 3 commits behind head on main. The diff coverage is n/a.

Additional details and impacted files

[](https://app.codecov.io/gh/elkodon/elkodon/pull/67?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=elkodon) ```diff @@ Coverage Diff @@ ## main #67 +/- ## ========================================== - Coverage 77.91% 77.88% -0.03% ========================================== Files 172 172 Lines 19036 19059 +23 ========================================== + Hits 14831 14845 +14 - Misses 4205 4214 +9 ``` [see 5 files with indirect coverage changes](https://app.codecov.io/gh/elkodon/elkodon/pull/67/indirect-changes?src=pr&el=tree-more&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=elkodon)