docs: Replace static page with mdBook site

Uses mdBook[1] to generate a documentation overview page instead of
the previous HTML site.

This makes it possible to add more elaborate documentation without
having to deal with finicky markup.

[1]: https://github.com/rust-lang-nursery/mdBook

1 files changed, 3 insertions, 0 deletions

diff --git a/tools/nixery/docs/theme/nixery.css b/tools/nixery/docs/theme/nixery.css
new file mode 100644
index 000000000000..c240e693d550
--- /dev/null
+++ b/tools/nixery/docs/theme/nixery.css
@@ -0,0 +1,3 @@
+h2, h3 {
+  margin-top: 1em;
+}