I would like to reproduce a feature GitHub and StachOverflow do have regarding user generated content (e.g. text posts).

For example, GitHub provides info about changes in texts of Issue posts:

Visual example

Github also returns GIT repo info (commits, diffs, etc.) in frontend somehow.

Hence I’m asking: How to work with GIT in Node.js and feed the data in a frontend app? And how to commit user input (text POST requests maybe) into a repo generated for him on server? Are there any convenient ready solutions? Maybe some tutorials and software architecture recommendations? Maybe you could recommend a Node Module implementing GIT API?