Clean up colors and docs

docs/configuration.md

@@ -23,3 +23,28 @@ aux_links:
 "Just the Docs on GitHub":
     - "//github.com/pmarsceill/just-the-docs"
 ```
+
+## Color scheme
+
+```yml
+# Color scheme currently only supports "dark" or nil (default)
+color_scheme: "dark"
+```
+<button class="btn js-toggle-dark-mode">Preview dark color scheme</button>
+
+<script>
+const toggleDarkMode = document.querySelector('.js-toggle-dark-mode')
+const cssFile = document.querySelector('[rel="stylesheet"]')
+const originalCssRef = cssFile.getAttribute('href')
+const darkModeCssRef = originalCssRef.replace('just-the-docs.css', 'dark-mode-preview.css')
+
+addEvent(toggleDarkMode, 'click', function(){
+if (cssFile.getAttribute('href') === originalCssRef) {
+cssFile.setAttribute('href', darkModeCssRef)
+} else {
+cssFile.setAttribute('href', originalCssRef)
+}
+})
+</script>
+
+See [Customization]({{site.baseurl }}{% link docs/customization.md %}) for more information.