I don't know of anyone who has set up Q2A to work with composer. It's something I plan on doing at some point in the future, but the codebase is not ready for it yet. Maybe in Q2A 2.0.
However, you can run Q2A from the Github repo, so in your project you could get up Q2A in a subfolder (or as a git submodule), and use a post-update hook in Composer:
"scripts": {
"post-update-cmd": [
"git -C q2a/ pull"
],
}
Hope that helps!