git clone --recursive https://github.com/rustdesk/doc.rustdesk.com.git
cd docs.rustdesk.com
hugo server
If you found any bugs, stop the server and delete public folder and run again.
You could make changes and than push and create PR.
Sync your fork at GitHub UI or create new branch that points to upstream.
Make sure you've checkout to right branch, and run:
git pull --recurse-submodules
If you're cloned from here, just run the command.