Add suggestions about typechecking and linting to EiC checklist for new submissions

[eliotwrobson]

Per discussion in slack, we should add optional checks to the EiC checklist for new / pre submissions for automated typechecking and linting, preferably added with CI. These won't be hard requirements (especially for typechecking since that can be tricky to get working properly), but is meant as a blanket recommendation to improve overall package quality and ease the review process.

Also perhaps worth suggesting uv, ruff, and mypy as recommended tools for most situations (which might tie into more in-depth working examples for packages we might create later).