docs: add doc about how to setup devenv and setup vscode tasks for basic automation

.vscode/tasks.json

@@ -0,0 +1,23 @@
+{
+    // See https://go.microsoft.com/fwlink/?LinkId=733558
+    // for the documentation about the tasks.json format
+    "version": "2.0.0",
+    "tasks": [
+        {
+            "label": "Start dev server",
+            "type": "shell",
+            "command": "browser-sync start --server build/ --watch"
+        },
+        {
+            "label": "Build",
+            "group": "build",
+            "type": "shell",
+            "command": "nox -R -s build"
+        },
+        {
+            "label": "Extract localization messages",
+            "type": "shell",
+            "command": "nox -R -s extract_messages"
+        }
+    ]
+}

README.md

@@ -58,3 +58,10 @@ We use the BEM naming convention with the scheme
 See https://getbem.com/naming/ for insigths on the BEM naming convention.
 
 We use SASS as a CSS extension language (https://sass-lang.com/).
+
+### Dev env
+
+Install the following dependencies to be able to test the website locally:
+```sh
+npm install -g browser-sync
+```