Noya desktop app

[dabbott]

We should distribute a cross-platform desktop app for Windows/Mac/Linux.

Most likely, we should use Electron to start, but potentially explore React Native Mac/Windows in the future. There shouldn't be any fundamental challenges with Electron, while React Native would be much more exploratory (and no native Linux support yet, afaik).

Setup

• It looks like there's a TypeScript template we can use: https://www.electronforge.io/templates/typescript-+-webpack-template
• Since we're fully open source, it looks like we can release updates directly via GitHub releases: https://www.electronforge.io/config/publishers/github
• Ideally the electron app could be another package in this monorepo, e.g. packages/noya-desktop. But if that's not feasible, it could sit at the top level of this repo and we can restructure as needed

Features

• We should be able to open multiple windows, each containing a different document. We don't need to be able to open the same document in multiple windows
• On Mac only, the app should remain open even if no windows are open
• We should use the Electron Menu API to have application-level menus that can dispatch actions within the app
• System fonts! We should expose system fonts for use in design files. This may be hard to do, so we can probably do this last

Implementation

We should aim to have as little electron-specific code as possible, and instead put most code in the other packages. The electron code will ideally be all operating-system-related glue code.