Reconsider my file naming convention and default exports

If this React `React.lazy` RFC lands will change the naming convention to be `Buttons.tsx` (instead of `buttons.tsx`) and sunset the default exports issues, probably move into a blog post with a mention of its okay as the conventions beat personal preference :rose:

Start by reviewing the React.lazy RFC context referenced in the issue and the current guidance on file naming and default exports. Decide whether to adopt Buttons.tsx naming, sunset the default-export discussion, and move it into a blog post; done means the convention and rationale are documented consistently.

Written by the indexing model from the issue text.