Review all tips for relevance to deep learning and biology

To keep the scope of this article focused, the tips should be about deep learning in biology. Several tips only pertain to one or the other. I recommend we add more biology examples to the tips that are mostly about deep learning to keep the article relevant.

I'm less sure about what to do for the tips that describe best practices for machine learning or statistics but are not specific to deep learning. For example, the first paragraphs of [Tip 4](https://benjamin-lee.github.io/deep-rules/#know-your-problem) are all essential but not deep learning-specific.

Review all tips in the article, starting with the deep-learning and biology focus described in the issue and the first paragraphs of Tip 4, “Know Your Problem.” Decide which tips need biology examples or narrowing, and finish when the article consistently stays relevant to deep learning in biology while retaining essential general guidance.

Written by the indexing model from the issue text.