add global styles, theme, prism styling, and add html Document to static.config

Add WIP source-markdown plugin for react-static

Add frontmatter and headings data

Update yarn.lock

Add image support by moving parsing to loader

Add transform fix for markdown links

WIP: begin adding sidebar back with new markdown data structure

add other sections to sidebar and refactor

Add opts.pathPrefix support to source-markdown

WIP: change data structure of pages, add sharedData

Refactor node.api.js to remove non-reloadable state

WIP: change structure to be sorted by section instead of by page in react

Add id props to heading elements in source-markdown loader

Clean up packages/site by removing static-* helpers

Remove empty paragraphs from source-markdown output

WIP: make sidebar work with sections instead of pages

Remove old styling in pages/site

Add new structure for MDXComponents

Replace HAST conversion with MDX's implementation

Implement code highlighting component with prism-react-renderer

Fix h1 override from frontmatter in source-markdown

move parse markdown page logic to separate file, add order and title to md files, move grouping logic from hook into plugin

Add initial recursive grouping logic

Add normalisation for page.path

Add improved default sorting

fixes sidebar again

Fix URL remapping in source-markdown/loader

Implement relative routing for site sidebar

Limit collected headings to depth <= 3

Move parseMarkdown to markdown

Move all browser utils to source-markdown/index.js

Add template override option to frontmatter

Add support for order overrides in plugin config

Move plugin to react-static-plugin-md-pages package

See: https://github.com/kitten/react-static-plugin-md-pages

Fix linting issues