rewrite type docs in markdown

docs/css.html

@@ -8,9 +8,9 @@ lead: "Global CSS settings, fundamental HTML elements styled and enhanced with e
 {% markdown %}
   {% include css/overview.md %}
   {% include css/grid.md %}
+  {% include css/type.md %}
 {% endmarkdown %}
 
-{% include css/type.html %}
 {% include css/code.html %}
 {% include css/tables.html %}
 {% include css/forms.html %}