Git doesn't support this, but Github does via SVN. If you check out your code with subversion, Github will essentially convert the repo from git to subversion on the backend. There is a popular javascript library 'lodash' i will use this library as an example
1.copy the URL of git repo to your clipboard.
https://github.com/lodash/lodash
2. Modify this url for subversion:
If you want to download the folder at /docs from the master branch, so you need to append trunk/docs. Full URL is now https://github.com/lodash/lodash/trunk/docs
3. Download that folder to the command line using:
svn checkout https://github.com/lodash/lodash/trunk/docs
Note: It may take up to 30 sec to convert large repositories.
For more commands like this please go through the following tutorial that will help you understand the git