Add initial implementation of Simple Gantt chart and sample names list

- Created index.html for the Gantt chart with sample tasks and configurations.
- Added styles for the Gantt chart and linked necessary CSS and JS files.
- Introduced a names.txt file containing a list of names for potential use in the application.

libraries/functions.js

@@ -13,7 +13,7 @@ $( document ).ready(function()
   $( 'input.datetime' ).datetimepicker({
     language: 'pl',
     autoClose: true,
-    disabledDates: false,
+    disabledDates: [],
     pickTime: false,
     format: 'YYYY-MM-DD',
   });