Feature request: loading of local self-contained HTML file

Hello, I'd like to load a file from local storage (offline).
Usecase: I have a self-contained static HTML generated from a song database (crosslinked indexed songbook with accords and song lyrics) tahat I'd like to open fullscreen on a tablet (Boox-X 14'' eInk).

Now I can load it from a web host, but I'd like it to work off-grid.
Option to load a folder (loading additional resources) would be nice, but not neccesary for me (I've made the HTML originally to be converted into paged PDF, but viewing that on a 14'' device unnecesarily splits the longer songs).
Folder loading would allow creating more complex semi-offline apps :-)