Generation Form: customize the PWA

[qtipee]

Add the following options to the generation form:

• Image or color background
• Font
• External link for the audio files (if hosted on another server)
• App design (offer the choice between different themes and a no-theme design ; useful to customise the design oneself afterwards)
• (Audio files to automatically cache ; not sure if useful for the end user)

[qtipee]

The structure and design of the generating app will be partly reviewed and improved during this issue.

[qtipee]

After some reflexion, this issue won't be implemented for now. The application will offer a choice between generating a PWA with no design - so that the end user can customize oneself its application - and some predefined themes (like light theme, dark theme, ...).

I'll let this issue open, because I think it would be great to let the user customize its PWA from the application, but with a lot more options that just the background color and the font.

This is no more a priority for this project.