Update instructions.md

[srcsintheta]

Exercise should state restrictions of the online tests.

[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?

• Concept exercise changed

  • 🌲 Do prerequisites and practices in config.json need to be updated?
  • 📖 Does the concept introduction provide all necessary information to solve this exercise?

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Automated comment created by PR Commenter 🤖.

[angelikatyborska]

Hi! Thank you for the contribution.

Bird count is a learning exercise. When you start it, you are first presented with an introduction to the concept it's supposed to teach (in this case recursion), and only then with the exercise instructions. This order of content and emphasis on the concept should imply that the concept must be used to solve the exercise. This is true of every single learning exercise, for all programming languages, not just Elixir. It's a basic assumption for all learning exercises and shouldn't need to be repeated in each exercise's introductions.

Additionally, learning exercises are meant for people completely new to the specific programming language. When writing content for learning exercises, I need to assume that the reader is not familiar with any Elixir concepts except for the ones already covered by previous learning exercises. Adding the note you're suggesting would be mentioning concepts that learners haven't heard about before, which might cause confusion and fear that they missed or forgot something.

For those two reasons, I feel like it would not be beneficial to accept the changes you're proposing. Sorry!