This refactoring re-organizes the `site` folder to have a nested `src` folder.
Originally, [we wanted to keep the directory structure shallow](https://github.com/coder/coder/pull/8#issuecomment-1009578910) - but there were two points that motivated this change to introduce the `src` level.
1. We have several non-`src` folders now (`e2e`, `static`, `html_templates`, `.storybook`)
2. Having a `src` folder makes it easier to run XState Typegen
So given those two data points - I believe it makes sense to revisit that and introduce a `src` folder.
