Added a new section Demoscene to built-with-assemblyscript.md (#198)

Author: dipdowel

src/built-with-assemblyscript.md

@@ -51,6 +51,11 @@ A place for all things AssemblyScript. Feel free to add your projects and applic
 * [visitor-as](https://github.com/willemneal/visitor-as)<br />
   Tools for creating compiler transformers.
 
+## Demoscene
+
+* [Hoofdkantoor WASM Demo](https://wasm-demo.codument.com)<br />
+  A demo built with AssemblyScript (also TS and Web Audio API). It's an homage to the old school Demoscene of the early 90s.
+
 ## Editors
 
 * [Fastly Terrarium](https://wasm.fastlylabs.com/)<br />