Use case: We want to sync a new repo / vault down from GitHub to my local computer.
There are several methods/tools you can use. Choose one that suits you best.
You can read and edit (if you have permissions) the wiki through the GitHub web interface. It's very clunky, but it can be doe.
cd ~/Documents/GitHub git clone https:// ...
- easiest, but sort of inscrutable unless you're familiar with command line
Use the Command Palette in Obsidian and search for "clone".
No other tool required, but the user interface and workflow is a little clunky.
If you're using an IDE for other things, you can also use its Git integration for wikis.
Only good if you're familiar with your IDE, and find it easier than using Obsidian Git.
GitHub Desktop is a free and open source Git UI client. It also has good authentication integration with GitHub.
You may find other Git UI clients useful. See Git GUI Clients.