Publish post 'Test nginx Configuration Directives' (#3)

Sitegen had some problems rendering `$host$request_uri` and `$$ct` so I had to make some changes to the Markdown renderer.

Reviewed-on: #3

README.md

@@ -56,9 +56,13 @@
 
     $ make build
 
+### build a single file
+
+    $ make build file=index.html
+
 ### start dev server
 
-    $ make
+    $ make serve
 
 Visit `localhost:8080` in web browser