suewonjp

First, clone your github wiki to your local machine

1. Checkout your repository wiki via git.
    - You can find the URL at the lower-right of your wiki page (look for the label "Clone this wiki locally")
2. Now that you have pulled down a local copy of your github repo wiki, create a new file in the repo called _Sidebar.md  - Note that other names might not work.
3. Within the newly created _Sidebar.md file, you can add appropriate [[link]] markdown syntax.
4. Add your new file to the local repository, and push via git push origin master.

With the same procedure, you can add a header(_Header.md) and footer(_Footer.md) file.