You can install the latest version of the extension via the Visual Studio Marketplace here.
Using a VSIX file
Download the VSIX file and follow the steps on your VSCode:
Go to the "Extensions" pane
Click on the ... on the top right of the "Extensions" pane
Select "Install from VSIX"
Select the VSIX file you downloaded and click install
Development
For the development you'll need to use VSCode
Install Node/Npm
After forking/cloning the repository, run:
npm install
npm run compile
And to run/test the extension, go the the Run pane and hit the green button on Run Extension. This will open a new VSCode window with the extension enabled.