Enhance the import order

[pangolingo]

• add more groupings so similar directories are grouped
• enforce newlines between import groups for readability
• alphabetize imports
• warn about import order instead of erroring

This is fairly opinionated. I'd be happy to leave the grouping as is, instead of grouping parent and sibling imports.

This import rule is only good if you have an autoformatter that can do it for you (VSCode does it for me). Otherwise it's very painful.

[pangolingo]

I'm going to close this out because I want to use the Typescript autoformatter's defaults and not force folks to use eslint unnecessarily. In the future if I feel like spaces between import groups or alphabetization would provide a big benefit, I may reopen this PR.

[stevehanson]

@pangolingo definitely open to continuing the discussion!