Add library recommendations.

[quadrupleslap]

Recommending other libraries is really important because you can't make an app with just a window. But, at the very least, they have to work inside the stupidly annoying UWP sandbox, and it'd be ideal if they worked on iOS and Android. Things that might be useful:

• a filepicker - if we're extremely lucky the one inside the web view can punch holes in the sandbox
• notifications - maybe HTML5 notifications work
• converting the executable into an app - this is super, super important for Windows and macOS
• application data directories - the app_dirs crate looks really good

[Ortham]

I've used tinyfiledialogs and nfd-rs for file and folder pickers with webview. The former is poorly-documented (though there's not much to it) but the latter doesn't work well on macOS (crashes if called on a non-main thread, windows don't close if followed by an event loop). I've also used app_dirs, would 👍 that recommendation.

[quadrupleslap]

The current method to include things like binary content is by using a server on an ephemeral port, and for that, these libraries are the best that I've found:

• https://github.com/tomaka/rouille looks like the easiest-to-use web framework out there right now.
• https://github.com/tilpner/includedir to embed files into the executable so they can be served easily.

[quadrupleslap]

tinyfiledialogs has a nice API, but I'm not sure if it plays nicely with the application sandbox, because it calls out to AppleScript for every dialog (I'm still not sure if that's a brilliant or a terrible idea.) I think the most pragmatic solution would be to make a tether-dialogs crate that wraps nfd-rs and extends Window with those methods, to statically verify that the application is on the main thread.

[mdtusz]

In addition, menubar menu-items are something I imagine many people (myself included) would want to be able to use. Whether this is provided by tether, or a third-party library I'm unsure of.