[TYPO3-english] Editing the introduction package HMENU

[Stewart Dinnage]

Hi All
    I'm new to typo3, I have successfully installed a typo3 7.6.0 site and the introduction package to my development server.
I'm very interested in how to customise typo3 layouts so I'm experimenting with the introduction package at the moment.

Has anyone got any pointers on how to edit the menu system as I find it difficult to locate the appropriate files, I'd like to implement a bootstrap 3 smartmenu like this

goto vadikom.github.io/smartmenus/src/demo/bootstrap-navbar.html 

Into the site layout.

Any advice or details of file locations warmly welcomed...