pop-count: rename to eliuds-eggs

[ErikSchierboom]

We are renaming the pop-count exercise to eliuds-eggs. See exercism/problem-specifications#2382 for more information.

---

This PR renames pop-count to eliuds-eggs. We have attempted to rename everything that is automatable, but you may need to make specific changes in the files.

If you could prioritise finishing and merging this, we would be grateful, so we can get the exercise in the correct state across Exercism. Please let me know if you have any questions.

Thanks! 🙂

[github-actions]

Thank you for contributing to exercism/elixir 💜 🎉. This is an automated PR comment 🤖 for the maintainers of this repository that helps with the PR review process. You can safely ignore it and wait for a maintainer to review your changes.

Based on the files changed in this PR, it would be good to pay attention to the following details when reviewing the PR:

• General steps

  • 🏆 Does this PR need to receive a label with a reputation modifier (x:size/{tiny,small,medium,large,massive})? (A medium reputation amount is awarded by default, see docs)

• Any exercise changed

  • 👤 Does the author of the PR need to be added as an author or contributor in <exercise>/.meta/config.json (see docs)?
  • 🔬 Do the analyzer and the analyzer comments exist for this exercise? Do they need to be changed?
  • 📜 Does the design file (<exercise>/.meta/design.md) need to be updated to document new implementation decisions?

• Practice exercise changed

  • 🌲 Do prerequisites, practices, and difficulty in config.json need to be updated?
  • 🧑‍🏫 Are the changes in accordance with the community-wide problem specifiations?

• Practice exercise tests changed

  • ⚪️ Are all tests except the first one skipped?
  • 📜 Does <exercise>/.meta/tests.toml need updating?

---

Automated comment created by PR Commenter 🤖.

[jiegillet]

Thanks for reviewing @angelikatyborska. I made so many mistakes working on this, I had no confidence 😅