new-tab pages for chromebook users.
for the file to open as you open a new-tab you whould need to install new-tab redirect extetion on your chromebook located here https://chrome.google.com/webstore/detail/new-tab-redirect/icpgjfneehieebagbmdbhnlpiopdcmna and after that click extentions --> new-tab redirect --> options and you should be presented with a screen where it says redirect url put the file path(you new-tab page) there. thanks to https://github.com/Axarva for the base of index.html index2.html.
Edit: forgot who make index3.html but thx