* Add H and Section components for context-aware headings
* Switch to using the new context-aware heading and section components
* Style header by class name, not heading level
* Add our client dir to the modules list for Jest
We already have this setting in webpack, but Jest doesn’t pick up on that
* Refactor dashboard layout into new Layout components
* Style the new layout
* Use Slot/Fill for the Header component
* Center cards, fixed size for sidebar
* Only set the box-sizing on things within our app
* Make app the full height of the wp-admin frame
* Add styles to show/hide sidebar
* Toggle the sidebar
* Wrap router around entire Layout, use page setting to show/hide sidebar on page
* Fix the styles on show/hide buttons, add title & close button to the sidebar
* Use a min-height on visible sidebars
* Add/update READMEs
* Update space between main content & sidebar