react + material-ui basic app shell
Material-UI (https://material-ui.com/) is a popular React-based component Framework. They give some good examples of app building blocks such as menu items on a left-side pane, which they call drawers. Open source frameworks such as react most wanted (https://www.react-most-wanted.com/) give you complete app shells to jump-start your app with. However, the architecture can be a bit complex and the lack of documentation may scare some developers away.
There is a sweet-spot in between: A simple react app shell that is easy enough to grok over and which developers can use to put a bunch of pages together and make an app of. This is the purpose of rxshell.
The architecture is pretty straightforward. In the pages folder, create new folders and drop your React components that share a UI in that folder. There is a single component called AppBar under the components folder which builds a drawer-based menu for all your components, routes URLs to your components, and provides for a collapsed and semi-collapsed menu. Edit AppBar.js and add your components and URLs. Simple examples illustrate the process. The tristate expanded/semi-collapsed/collapsed menu may be a bit complex to grok, but you don't need to understand how it works (hint: React's clsx() API and hiding chevron IconButtons are the main engine).
Directions: download, open a cmd shell at the root, yarn install, yarn start
Enjoy!