accessibility: screenreader and keyboard nav
This MR addresses the issues that came up during my accessibility testing (outline in #22 (closed)). Specifically,
- Made prev/next buttons focusable and have an aria label of "next page" or "previous page"
- Made the navigation tracker circles focusable and have aria labels that say "click to go to page xx"
Other minor changes:
- updated disclaimer to provisional re: release guidelines
- updated code.json to include to-be-created v1.0.0 and correct main version text/statuses
- updated data viz to have larger fonts and better white space to look better on mobile sizes
- small css tweaks to fit better on small mobile screens
What focus on navigation tracker circles looks like:
What focus on the next/prev buttons looks like: