Add webapp overview documentation

Author: Julien Neuhart

docs/docs/4_Web Application/4_1_Overview.md

@@ -1,4 +1,14 @@
 ---
 title: Overview
 slug: /webapp/overview
----
+---
+
+We built the web application with [Nuxt.js](https://nuxtjs.org).
+
+The web application is the frontend of the boilerplate.
+
+While you may find most of the information in the [official documentation](https://nuxtjs.org/docs/2.x/get-started/installation),
+it is essential to note that:
+
+* Most of the logic (use cases, validations, access control) occurs in the API.
+* The web application's primary goal is literally to be a UI for the API.