mermaid: fix official url in docs matcornic#11

exampleSite/content/credits.en.md

@@ -11,7 +11,7 @@ Special thanks to [@matcornic](https://github.com/matcornic) for his work on [le
 
 ## Packages and libraries
 
-* [mermaid](https://knsv.github.io/mermaid) - generation of diagram and flowchart from text in a similar manner as markdown
+* [mermaid](https://mermaid-js.github.io/mermaid) - generation of diagram and flowchart from text in a similar manner as markdown
 * [font awesome](http://fontawesome.io/) - the iconic font and CSS framework
 * [jQuery](https://jquery.com) - The Write Less, Do More, JavaScript Library
 * [lunr](https://lunrjs.com) - Lunr enables you to provide a great search experience without the need for external, server-side, search services...