We are not planning to support the Roblox marketplace for our framework, as it can easily break existing systems due to auto-update functionality.
You can use Rojo to sync local files with Roblox Studio. Quebec uses this in combination with to update Quebec reliably.
We provide a GitHub Repository for the Rojo template. You'll find setup instructions in the repository README file.
Go to the Releases tab of the Quebec GitHub repository, and download the Quebec.rbxm of the latest release. You can then import this file into Roblox Studio. We recommend putting the ModuleScript into ReplicatedStorage, to avoid duplicates.
You can also just download the source code of the latest release under the Releases tab, however you will have to use a tool like Rojo to sync those files with your game. We just recommend using the Rojo Template in that case.