DOC: code gallery

Summary

New code gallery section in documentation, with one example.

Focus

• Is this a viable starting point for more examples?
• Does the documentation compile?
• Does the example run and produce the desired result?

Test Environment

Documentation

1. make doc
2. Open html in browser xdg-open build/doc/html/index.html

Example code

1. Start empty CaosDB instance.
2. cd src/doc/gallery/
3. make test

Check List for the Author

Please, prepare your MR for a review. Be sure to write a summary and a focus and create gitlab comments for the reviewer. They should guide the reviewer through the changes, explain your changes and also point out open questions. For further good practices have a look at our review guidelines

• All automated tests pass
• Reference related Issues #82 (closed)
• Up-to-date CHANGELOG.md
• Add type hints in created/changed code
• Annotations in code (Gitlab comments)
  • Intent of new code
  • Problems with old code
  • Why this implementation?

Check List for the Reviewer

• I understand the intent of this MR
• All automated tests pass
• Up-to-date CHANGELOG.md
• The test environment setup works and the intended behavior is reproducible in the test environment
• In-code documentation and comments are up-to-date.
• Check: Are there spezifications? Are they satisfied?

For further good practices have a look at our review guidelines.