Add instructions on how to build a static, mirror website of the courses.

README.md

@@ -5,6 +5,8 @@ These are the sources of an instance of Grav tailored for the courses of M3P2.
 The plugins and themes are included.
 Only the php vendors are not included.
 
+## Run locally for fast development
+
 	composer install
 
 http://getcomposer.org/
@@ -29,6 +31,18 @@ And run locally
 
 	php -S localhost:8000 system/router.php
 
+## Mirror the courses to generate a static website
+
+This may come in handy when we'll want offline access
+
+    wget -mkxKE -e robots=off https://courses.m3p2.ljbac.com
+
+And then to browse locally, for example :
+
+    cd courses.m3p2.ljbac.com
+    
+    firefox index.html
+
 
 ## Upgrading vendors