Refactor docs, make a new website.

* Docs have been migrated from docbook to yaml + jinja2 + pandoc
* Created a new (basic) website for docs based on React + Tailwinds

web/utils/tailwind-preset.js

@@ -0,0 +1,62 @@
+const plugin = require('tailwindcss/plugin')
+const pluginTypography = require('@tailwindcss/typography')
+
+const hoveredSiblingPlugin = plugin(function ({ addVariant, e }) {
+  addVariant('hovered-sibling', ({ container }) => {
+    container.walkRules((rule) => {
+      rule.selector = `:hover + .hovered-sibling\\:${rule.selector.slice(1)}`
+    })
+  })
+})
+
+module.exports = {
+  theme: {
+    fontFamily: {
+      sans: [
+        'Inter',
+        'ui-sans-serif',
+        'system-ui',
+        '-apple-system',
+        'BlinkMacSystemFont',
+        'Segoe UI',
+        'Roboto',
+        'Helvetica Neue',
+        'Arial',
+        'Noto Sans',
+        'sans-serif',
+        'Apple Color Emoji',
+        'Segoe UI Emoji',
+        'Segoe UI Symbol',
+        'Noto Color Emoji',
+      ],
+      serif: [
+        'Inter',
+        'ui-serif',
+        'Georgia',
+        'Cambria',
+        'Times New Roman',
+        'Times',
+        'serif',
+      ],
+      mono: [
+        'Fira Code',
+        'ui-monospace',
+        'SFMono-Regular',
+        'Menlo',
+        'Monaco',
+        'Consolas',
+        'Liberation Mono',
+        'Courier New',
+        'monospace',
+      ],
+    },
+  },
+  variants: {
+    extend: {
+      borderRadius: ['first', 'last'],
+      borderWidth: ['last', 'hovered-sibling'],
+      typography: ['dark'],
+    },
+  },
+  plugins: [hoveredSiblingPlugin, pluginTypography],
+}