is that possible to import my project (HTML/CSS/JS) into any bootstrap editor and edit it from there?
I'm looking for a way that I can modify my existing web project using a visual editor (WYSIWYG).
Absolutely. Several Bootstrap WYSIWYG editors will allow you to copy over your existing HTML/CSS/JS. With Divshot you can import your entire project at once and have all of your files appear in a file tree as you might expect with any desktop based text editor or IDE. Just click the + icon in the navigator panel and select Upload Files. From there you can move, duplicate, delete or rename your files and manage them however you'd like!