NVM is the Node Version Manager, it lets you choose which node version should be exposed in the PATH variable.
This should not be a PR-setup where people have to create a pull request to get their addons submitted, that is a lot of unnecessary work for add-on developers. Your add-on website should proxy other git repos, i.e. you can add a database where people can add a add-on name ‘example’ to a database which points to a git URI ‘github.com/octocat/hello-world’.
In the top of your cli.py file you can add a shebang#!/usr/bin/env python3. This way you can rename the file to glitch-cli and users will be able to run it using ./glitch-cli.