docs: Updated HACKING.md

HACKING.md

@@ -1,17 +1,44 @@
 # Hacking Material Design for Bootstrap
 
-This project makes use of Gulp to build all our source codes.
+This project makes use Rollup and node-sass to build its assets.
 
-You can get a full list of available commands running:
+To watch all the files and get the compiled ones in the `dist/` folder, just run:
 
 ```
-npm run gulp -- --tasks
+npm run watch
 ```
 
-Then, simply run:
+You can also watch CSS or JS individually running:
 
 ```
-npm run gulp dist:default // or any other task name
+npm run watch:css
+# or
+npm run watch:js
 ```
 
 To trigger the relative task and run it.
+
+If you desire to compile the project for production, genering also the minified versions of it, run:
+
+```
+npm run build
+```
+
+Or if you prefer to compile only CSS or JS individually without minification:
+
+```
+npm run build:css
+# or
+npm run build:js
+```
+
+If you desire them to be minified, instead, run:
+
+
+```
+npm run build:css-min
+# or
+npm run build:js-min
+```
+
+To compile and minify the files.