Iām sure could be awesome to have manual for a game on the Play date console.
Like in old times we had manual with game cartridge.
For this great feature need to do:
invent lightweight text format, maybe with images, maybe based on md or maybe on some structural lang like yaml - that will be simple to limit with a scheme;
UI: reader app;
UI: possibility to know that manual for a game is existing;
UI: some button to start read manual - run reader app - in can be long press on a game in the Launcher app for example;
extend package manifest with field that points to manual, or just put it in the root/manual
It's a lot of work, but I write the content as a rough outline during development. Then it's a nice easy job to lay out the pages a day or two before release.
Digital manuals would be cool, we could use one or another of the existing ebook readers. Until then, I include reduced instructions on the title screen of my games.
We could even avoid having to download and sideload a text file if the games just wrote their manuals to the shared folder and the reader(s) added support for reading from there. I'm in favour!
Open standard as offered above is great, I agree. But I suppose it would be ideal to see an app/service built into the OS and declared format row manual.