Add image in example site and activate progressive

exampleSite/config.toml

@@ -21,6 +21,7 @@ description = "Example blog"
 logofile = "img/logo.png"
 faviconfile = "img/logo.png"
 highlightjs = true
+progressively = true
 lang = "en"
 github = "example"
 email = "you@example.com"

exampleSite/content/about.md

@@ -5,6 +5,8 @@ title = "About"
 
 _With this theme, it is possible to add small sections that only contains one page like this. It will automatically appears in the header, at the end._
 
+![image](./img/startup.jpg)
+
 Along with [Ford Prefect](https://en.wikipedia.org/wiki/Ford_Prefect_\(character\)), Dent barely escapes the Earth's destruction as it is demolished to make way for a *hyperspace bypass*. Arthur spends the next several years, still wearing his dressing gown, helplessly launched from crisis to crisis while trying to straighten out his lifestyle.  
  
 > He rather enjoys tea, but seems to have trouble obtaining it in the far reaches of the galaxy.